smaller spaces are more of a challenge, especially when you have to work round stuff, but no, it's not hard.
You want the final join to be in the smallest corner, maybe behind a door or place you are least likely to look as that's where the pattern is most likely to be mismatched.
A small pattern repeat is best, what sort of paper are you looking at?
If the walls have not been papered before it is a good idea to paste them, this is called sizeing....watered down paste that you slap on and leave to dry before you start...it stops the wall sooking all the moisture out of the paste on the paper before the stickyness takes hold, if that makes sense
Regardless of this I do tend to paste the wall and the paper, it works for me, but I do it very stingily if I do both.
Try and get decent quality paper, cheap stuff can stretch and bubble and rip if you are not careful.
I learned just through helping my dad, but there's surely "how to" videos on the www now, so have a go!!