I have a shimano Sahara 3000 and want braided line, but don't know what lbs line to use. I mostly do inshore saltwater and freshwater fishing. Thanks!

I'm no expert on the saltwater part, but 20lb would probably be a good place to start. 

As suggested, the 20# braid is a good match for a 3000.

Agreed.....I would use a leader too.  Size depends on your mission.

20 for inshore, but I suggest 15 for fresh water.  Longer casts, strong enough for almost anything fresh.