I like to do the least amount of work to get the bike functional first before I put a lot of work into it. That way I can check for things like a bent frame or fork before spending a lot of time and money cleaning, painting and lubing everything. Once I know the bike is going to work, I make a list of the things that I want to do and parts that I need.
If you are going to paint, make sure you let it cure for several days so you don't scratch it the first time you go to mount components.