In my experience spray painting bicycles, though rewarding, is ultimately a test in patience and proper application. I did a fair amount of research before spray painting a junker mtb. These are the following steps that I used:

Strip paint with aircraft remover
Sand down frame for good adhesion
Prep with alcohol and tack rags
1 Coat of Adhesion Promoter
1 Coats of Primer
Sand
1 Coat of Primer
Sand
1 Coat of Color
Sand
1 Coat of Color
Sand
1 Coat of Color
Sand
1 Coat of Clear
Sand
1 Coat of Sparkly Spray paint goop (the can splooged all over my paint and dripped horribly). Give up in frustration and let bicycle sit for a year.

I did wait at least a day between each coat, or at least several hours in 90 degree direct sunlight between each coat.

After letting it wear in the elements, I found even the best care would still cause the paint to scrape off. It's rather disheartening, and I was down about seventy dollars in supplies (1 Spray paint mask, tack rags, three cans of high quality Montana brand spray paint, good sand paper, etc).

But if you're still willing to go ahead with the project, I really suggest getting a 3M spraypaint mask with filters. It'll cost you money, but it's worth it. The first time I sneezed after spray painting without a mask was an enlightening moment: I sneezed out spraypaint colored snot. Think about your lungs!