refrigerating seeds with groist growing medium

I would like to try to grow an annual salvia and perennial rudbeckia from seed. In Eileen Powell's "From Seed To Bloom", it says both types need to be refrigerated with a moist growing medium for 2-3 weeks. What is the best way for a beginner to do that?

And, is the frige time included in the 6-8 weeks before last frost calculation, or should I add it on?

You don't need to put the seed in a moist growing medium-not sure why she says that .....I grow both seeds each year, and although I refrigerate the seeds before I germinate them, its only because I store all my seeds in the refrigerator before I germinate them. I usually get my seeds in late Dec or early Jan, and I germinate the salvia and rudbeckia in Feb, but if I just got the seeds in now, I would germinate them w/out refrigerating them.

If you want to do it that way, though, I doubt it would do any harm... There are some salvias that do require cold treatment, although I don't think it's needed for annual varieties. I would use either slighty moistened perlite or a paper towel (wet under the faucet and then wrung out until just damp, not dripping wet) in a baggie. Time for cold stratification is generally not included in those 6-8 weeks before last frost calculations.