Help - need practical advice on decorating

[dodgydonkeysdoodah]

I have a bit of redecoration to do - a total DIY novice but need to save some £££s. I have bought paint but have no idea how to "prep" ready for painting. Can anyone advise?
The emulsion on walls and ceiling I can handle, but the woodwork I am not so sure.
Room 1 - bathroom - a lot of white eggshell painted woodwork which merely needs a freshen up with more white eggshell - it was only done 3 or 4 years ago so one coat will probably do it.
Room 2- bedroom. I want to paint over white gloss woodwork with an off-white eggshell. It's not in terrible condition but it is quite old (10 years) and probably dirty.
All the paints I have bought are water based. I have no idea where to begin! Please help!

Best way to paint wood is to remove any loose flakes of paint, sand it down with a medium rough sandpaper, wipe down with white spirits, use an undercoat then, when dry, put in the top coat.

I would clean it first - a decent wipe with hot soapy water. Then a light sanding - wash again to get the dust off then paint.

I have done a lot of painting of woodwork in the past few weeks.. It's quite satisfying and not as messy as emulsion painting.