I just bought the tatula 100hs baitcaster. what kind of line works best for a baitcaster?

First, welcome to the forums.

 

You can spool with braid, mono, fluorocarbon... Give a little more info on what you plan to use it for and the suggestions will flow.

For ease of casting, mono is hard to beat. The others have their pluses, but mono is the easiest to use; in my opinion.

If you are new to baitcasters I would start with mono.  That way you're not out much money if you have to cut out a backlash.

Welcome to the forum.  Knowing rod power, cover, types of lures you will be fishing, cover, etc. would be a big help.  For everyday fishing locally, the majority of my Medium power rods carry 8# mono while a majority of my MH power rods carry 12# mono.  A friend fishing the same areas I do uses 15# mono almost exclusively on his baitcast reels.  Both of us feel our line selection is the right one.  As you probably can determine, there are no hard and fast rules....within reason.  I use 6# mono on a couple baitcast reels, but never would I use these reels in cover.