Lasagna Bed Help Wanted.

I decided to build a small bed this year and I just have a couple of questions that I know of and probably many that I haven't even thought of. So far I have a layer of coffee grounds followed by a layer of pears followed by a layer of mulched leaves. My questions are what am I missing in my mix?
Can I still add more coffee on top of the leaves?
I have access to horse manure should I add that?
Am I suppose to mix it or wait till spring?

Any and all help will be greatly appreciated.
Sandy