Sounds like you don't have too much experience with home projects (well, neither do I, but I have three contractor friends that employ me from time to time).
I would say self-installing anything having to do with electricity or plumbing is generally not a good idea. Unless you've done it before, su casa is probably not the best place to start.
Painting, replacing light fixtures - that's about the extent of DIY work I would do. Even window treatments are tough, unless you're doing something simple (rod and curtain, for example). Oh, my family tried wallpapering ourselves - NOT a good idea.