A few years ago, a friend and I painted the entire interior of my house. It was an eye-opening experience to me about what kinds of interior paint there are and what works best for new walls, old walls, for trim, and more.
If you get headaches from painting, chances are you are feeling the affect of Volatile Organic Compounds (VOC) that are reacting in your home environment. Those are the chemicals that make paint smell. There are more of them in oil-based paints, so if you are sensitive, choose a low VOC paint, or at least choose water-based enamel paint that cleans up faster, in cool water, and the smell goes away faster. I do not recommend oil-based paints for interior use, for that reason.
Latex paints come in a variety of finishes: Flat enamel, eggshell, satin, semi-gloss, and glossy. My preference is for the flat enamel. It is washable. I prefer it because it shows flaws less than finishes that go up the shininess scale. In the glossy category, every stray cat hair, patch job, or other flaws will show as if they have a spotlight on them. If your house is new, and has few to no flaws, and you like glossy, go for it. The only other caution about glossy, as far as my experience goes, is that the greater the sheen, the more glare. If you are light sensitive, don’t go for that type of finish.
Depending on how much traffic your bathroom gets, and if your bathroom is prone to mold, you may choose a special mold inhibiting bathroom paint. Your paint specialist at the home building or paint store can discuss this with you. I used flat enamel for the bathrooms and have had no problems with mold or peeling paint. You can choose a semi-gloss for your kitchen, if you and others are messy and spatter on the walls, but if you are neat, you can use flat enamel there, too.
For trim, no matter what color you choose, you need to choose a semi-gloss or glossy finish. These are more durable than flat enamel, and the glossy look makes the trim paint easier to clean. Trim should not blend in with the walls, so semi glossy or glossy is what you want, and in a color that contrasts with your wall color. White is standard, and it always looks good. I love the white trim I have around my doors and windows, the white baseboards, as well as for the chair rail in the living room and dining room. It looks crisp and clean, and it accentuates the wall colors.
One last tip: painting should really be done about every ten years because paint does eventually fade and lose its good looks. Happy redecorating, everyone!