[liveevil2000]

Here is what I did when I had 55 marines to paint.
Primer and base coat all the models (its the easiest thing to do)
Next I grab a few at a time (5-6) something I feel I can do in a couple of nights.
Apply 1 color at a time until complete (no basing)
Move on to the next bunch.
Once they are all painted I then do decals and basing as I feel this is the easiest step for me.
Then seal and play.
I did 55 marines in 2 weeks this way. 3 hours a night / 5 nights a week

This is what works for me. Just find a groove that works for you and go with it.