Here's an article with some tips on how to paint woodwork. I have to do some of mine as well this winter so I've checked these out too. The biggest thing that a lot of people skip is the preparation work. Don't just buy paint and start painting. Check the woodwork for dings or holes and fill them. Clean them well so they don't have any dust on them. A tip of mine is to keep a damp cloth handy just in case you accidentally touch the wall with a wet paint brush or drip on a floor. I also have "paint" clothes. They are simply older clothes that I don't wear anymore but I save them for paint. :) I'm the world's messiest painter, but I can get the job done. I hope some of the tips in the article can help you. Wishing you a successful paint job!
Maristela; maybe this will help