What kind of content are you looking for Sonrienta?
There's lots of non-infringing content (grrr--makes me irritable that some people think there isn't) and finding it is much of the fun of using LimeWire. Too, the new betas are supporting more searches for licensed material.
Infringing content usually is tied to well-publicized keywords, so discovering effective non-popular keywords is an interesting game. On the other hand, obscure keywords can reveal private or even shocking content. If you search outside mainstream keywords, be prepared for surprises.
Peerless could better tell you how to search for indy music.
For images, search for "dsc .jpg" or similar default digital still camera file names. Once you find some someone sharing those, browse them to find more and see what other keywords work. "Wallpaper" is also a common keyword here. Caution though: "amateur" will turn up lots of porn.
For video, if you stay away from popular movie names, you should be OK.
For text, start with the keyword of authors who died before the early 20th century (Shakespeare is a good example here).
Anything from
www.magnetmix.com is legit, so that's another place to start.
Other ways to find obscure keywords are the "what's new" type searches and double-clicking curious keywords on the "incoming searches" on the Monitor page (really only works if you are an ultrapeer and have discovered how to activate the incoming search display).
In short: find and use obscure keywords (the autogenerated spam is easy to spot with a bit of experience) and browse hosts that share files that don't use popular keywords in the filenames.