I've done a lot of painting and occasionally help my buddy when he gets a huge interior painting job. As far as paint, there are many things to consider. I value application time, finished look, and fumes during application as important features. My preferences are either Sherwin Williams Emerald or the Cashmere line. Pittsburgh Paint makes some great stuff too, but I'm not as familiar with their lines. My favorite is probably Cashmere by Sherwin Williams, but I paint with the Emerald stuff more these days. I find using good brushes and rollers as important as the paint choice, and some experience doesn't hurt either. Keep in mind the Emerald trim paint is an entirely different animal than the Emerald wall paint. Painting trim sucks. The finish look varies from brand to brand with semi-gloss in one brand looking more like satin in the other brand. Primer is rarely needed as latex on latex doesn't need one. Even the premium Behr stuff is just ok in my opinion once you paint regularly with the better Sherwin Williams and Pittsburgh lines. My buddy is at the point he won't do a paint project if the homeowner wants to supply their own paint. Brushes are highly personal and you get a bit of the "Chevy vs. Ford" kind of thing among serious paint professionals. I'm a real outlier in that I prefer Corona brushes with the Chinex bristles. Chinex makes cleanup much quicker as the paint doesn't really stick to the bristles. The only place I can find Corona brushes locally is at Spectrum Paints which also sells some quality Pittsburgh brand paints. I will only buy Sherwin Williams paint on sale during their 30% or 40% sales. They do those about once a month.