For close-up photography, look for a camera with a 'macro setting' or 'macro mode' . Though not a true macro lens, these settings will allow you to focus on objects at close range - typically 40cm but some even up to 20cm. As already stated - go for the the highest number of pixels you can afford. The final resolution will be so much better.
As with most things - "you gets what you pays for" Some 'budget' cameras may have all the whizzy things and a high number of pixels, but the resulting photos can be let down by a poor quality lens. I would strongly advise trying before buying. Just get your mits on a few different cameras to get an idea of how they feel, ease of use etc. Even if you have to go into Dixons to do this - after you've got the feel for the one(s) you like, just say you 'need to think about it' and go and order it off the net or something!!!