How do I bake boneless, skinless chicken breasts?

I wouldn't use olive oil if I were you - it might burn. If the chicken is fully defrosted, season it and put the sauce on it and leave it in a bowl for at least a few hours so the chicken can soak up the flavor. 350 is the right temp. You probably only need it in for 20-25 minutes, but I'd leave it in longer just in case.

Boneless skinless chicken breasts are bland and don't have the best texture, so you need to flavor them well and not over cook them or let them dry out. Marinating will certainly help. Brining, or just adding salt to the marinade will help keep them from drying out. If you put a boneless skinless chicken breast on a tray and bake it for 30 minutes you will get a dry, hard, tasteless piece of meat. Try this instead: Wash and dry the chicken. Marinate it in olive oil (disregard the answer that says olive oil will burn - that's not true) and your choice of seasonings (I might use curry powder and lemon juice). Put the chicken on a foil lined tray and bake at 350° for ten minutes per inch of thickness. So if the chicken is two inches thick cook it for 20 minutes. Check for doneness by pressing with s finger. When it's cooked all the way through it won't feel mushy. If you want to add texture, then after marinating the chicken wipe it off, roll it in egg wash and then cracker or bread crumbs or panko, etc. then cook it.

Whatever you do DON'T WASH THE CHICKEN !!! All that does is spread any bacteria around.

Boneless skinless chicken breast can easily dry out in the oven. I much prefer to pan fry on the stove top. Here's what you do: rinse and trim your breasts, and pat dry. Wrap in plastic wrap, set on the counter, and pound with medium force with a pot to even out the thickness of the chicken. Should be about 1/2 to 3/4 inch thick when your done. Heat a fry pan till hot - water sprinkled on the pan sputters and almost immediately evaporates. Salt the chicken (nothing else) and add 1 tbs of oil to the pan (not butter....butter will burn). Set the chicken breast in the pan and it will sizzle loudly. Make sure the breast has been patted dry or it will splatter oil. Fry the breast on each side for 4 min each, then remove from the pan. Sprinkle pepper on the breast and let it rest a moment. If you want to make a nice little sauce then, saute your red peppers and onion in the pan drippings left over from the chicken (make sure you turn it down to medium heat). After 5 min or so, add your parsley and some hot sauce if desired. Should take 10 min total, your chicken will have a nice brown crust and be very tender and juicy on the inside. Remember, with all chicken, the juices should run clear! That indicates that the meat has been sufficiently cooked. Good luck and let me know how if goes if you try this method.