I started sailing on a H16, and found it a fine boat to learn on. I only had it about 7 months before selling it to move up to an 18' boat (as everyone I sailed with soloed 18' boats).

I currently have an '80s H14T I use for heavy-weather sailing. I have the old 5-batten mainsail and no jib, but I do have a dolphin-striker and trapeze kit. Makes for a fun ride when you really shouldn't be out on the water!

After checking out the hulls- these are the things I'd look for:
First, a dolphin-striker and trapeze- it's hardly catamaran sailing if you can't get out on the wire!
Second, a six-batten mainsail. It's a lot bigger than the five-batten version.
Third, a jib. I put this last because I only sail my H14 in conditions that would have me furling the jib anyhow. Also, it's easy enough to add a jib later.

Look on EBAY, there are plenty of H14s there right now.

Dan ,
Don't let all these people tell you that a H14 is not a good boat to learn on. It is. It may not be made of carbon fiber with a snuffer, but it's simplicity is it's key. You can trailer,rig , launch and be sailing in less time than the other guys can step their mast. That is if they brought someone to help. Plus there are many of them available and they are bulletproof. Let's see how some other boats fare after 20 years(average age). I have owned and raced many cats in the last 30 years. I now own 2 H14s. In the local regattas, they are the largest class. good luck, I know you'll enjoy