Should I add bagged fertilizer AND manure to my veg garden?

This is my second year with a veggie garden at my new home, first year if you dont count my husbands lame attempt last year when I checked out early because he planted my seedlings and seeds before I got home from work and placed them too close together so it was a mangled mess by mid July. This year Ive claimed the space and its all mine. I have everything planned but im really a novice gardener so some help would be nice. I read an article that says 300 lbs of manure is sufficient for a 1000 sq.ft. space. I only have a 500 sq.ft. space. so I am going to get 150lbs of mushroom manure today and re-till the ground to mix it together before I plant on Monday. My question: I read another article that says Espoma Garden Tone and Tomato Tone works wonders on a vegetable garden. Should i apply the garden tone along with my manure since manure is in itself a fertilizer?? I dont want to over fertilize. Should I wait and use the Espoma later on in the season as a "pick me up" for my flowering veggies?? That and any other veggie garden advice would be lovely thanks!!

There are many kinds of manure, and the rate and benefits are quite variable.
Bagged products:
Steer manure comes from feed lots, and can be quite salty. It is not usually very high in the actual fertilizer elements. It is more like a soil amendment, and not a very good one. I would not use very much, or very often. If I ever get any, I will spread it around, share it among all the beds so no one bed gets too much. I never buy it.
Chicken manure may include some bedding, but is usually higher in the actual nutrients that make it fertilizer. It can be so hot it burns the plants. A little goes a long way. This one also I will spread around in small amounts to each bed. If there is a sale on it, I will buy a few bags.
Other manures: Bat Guano, Worm Castings: Read the label, and do not over use. To me, these are overpriced and not worth the cost.

Loose material:
Horse manure with stall cleanings is available here in any quantity I want. Just take my truck to the stables, and they have a tractor to load it. They bed the stalls with either rice hulls or pine shavings. Rarely other bedding. The bedding is conserved in the stalls, they rake out only the wet material and the actual manure. Horse manure is very low in the fertilizer elements, but urine is high in ammonia, a nitrogen source. When this is added to the bedding, the blend makes a nice compost, and when this is added to the local soils it is a very good way to improve the soils. I have even planted the vegies in several inches of this material, without rototilling it in. I layered it on the surface and watered it, and allowed it to compost for just a month or so. (This is called sheet composting, when stuff is spread like this to compost).

When you are looking for soil amendments, compost and similar products you need to know your local soil. For example, if you are gardening where pine trees grew, and there is many years worth of pine needles in the soil, I would avoid pine shavings, and probably most other conifer products. If you are gardening in an old ranch, and there were cattle or horses the opposite might be true: You want the sawdust and similar materials, but probably should not add manures.

Bagged fertilizers:
There are several basic concepts and these can be mixed in any product.

Nitrogen (N) grows leaves. This is the first number on a bag of fertilizer. Most vegies do not need a lot of N, but they need some.
Phophorus (P) grows stems, roots and fruit. This is the second number on a bag of fertilizer. Most vegies need a fair amount of phosphorus.
Potassium (K) helps the plants with water balance and a lot more. This is the third number on a bag of fertilizer. Most vegies need a fair amount of potassium.
Trace minerals, especially Iron (Fe) help the plants make enzymes and a lot more. They are needed in small amounts.

You need to know what your soil has already before you add a lot of fertilizer. There are soil test kits available for home use, or you can send off samples of your soil. The home kits work well enough for what we do in most cases. Test N, P, K, Iron (if that kit is available) and pH.
Here is a really simple test: Does your soil grow weeds well? Are they dense, dark green? Then it probably has enough of the fertilizers to get the first crop grown.

Fertilizers are available in several forms.
Chemical fertilizers mostly become available to the plants very quickly, and can get washed out of the soil quickly, too. If the package says to add it once a week, or at every watering, then you know it is fast release. Try using half the label amount at first. Some of these fertilizers are not very friendly to soil microorganisms.
Organic fertilizers are mostly slower release. They are often materials that need to be composted to release the fertilizer. Blood meal, bone meal, cottonseed meal, and many ground minerals like greensand and oyster shell powder are these sorts of fertilizers.
Chemical fertilizers can be manufactured in a way that makes them slow release. Osmocote is one such product. The label will say something like 'Feeds plants for months'. or 'Apply once per season'.

Soil Amendment is something that is added to the soil, often in large amounts, but is not a fertilizer, or it may have trace amounts of the fertilizer elements, but not enough to grow a crop. Compost, mulch, soil conditioner and similar terms are used, but they all have the similar properties: Not enough fertilizer to grow the crop. They can be very helpful when rototilled into the soil, or layered on top as a mulch, so get plenty of whatever is available, just do not call it fertilizer. They loosen the soil, and do a lot more. Usually soil amendments are added once a year, and you can get several crops (depending on your climate) in one year.
As organic matter, soil amendments break down to release the elements so they are available to the plants. However, there are also a lot of microorganisms living in the soil and these organisms also need the elements that are released by the soil amendments. This can mean that soil amendments contain enough fertilizer so they will decompose just fine, but not offer enough to feed the plants. Many manures are like this. A nice blend of materials in a compost pile are like this.

Fertilizer is the actual elements that plants need to grow. The things plants need in small amounts (trace elements) might already be in the soil, the water or the soil amendment. Or they might not. (Iron is a good example- many soils are low in iron, and most soil amendments do not add much)
The things plants need in larger quantities almost always have to be added to get the best crop year after year. N, P, K and usually Fe are the most common elements needed. If you use a fast release fertilizer you will have to apply it several times through the growing season, do not apply too much at any one time.
If you use a slow release material, either an organic product, or a manufactured material, read the label. You might be OK with one application for fast growing crops, but may need to add some for the crops that grow for more than a few months. If you have been adding top quality compost for several years you might have added enough material that the soil is finally becoming rich enough so you might not have to add much fertilizer.

How I do this:
I have gardened in my soil for so long I know what it needs.
I add organic matter (leaves, manure, last season's mulch and so on) and certain fertilizers and minerals once a year, and rototill them in.
Then I plant, and add mulch on the surface. Through the growing season I add more fertilizer to certain crops, but not very much. I like using organic fertilizers, knowing they are better for the soil microorganisms, but I will also use chemical fertilizers, just not very much.
At the end of the season I will clean up the area, and either allow it to rest by adding some organic fertilizer and sheet compost something like leaves and grass clippings, or else I will rototill more compost, manure and fertilizer into the area and plant right away.