PHP PDO Database Wrapper
Is this a good way to go? How can I improve the class? Any suggestions in general?


Right now, your class doesn't really add any functionality to PDO. It basically just renames it's methods (to names other programmers will now have to get familiar with), and reduces it's flexibility and functionality. 

The only advantage you gain currently is that you save typing SELECT, FROM, and WHERE. I don't think that this is worth it.

Misc


use spaces around . for increased readability.
sth is a pretty common name, so it isn't that bad, but something like selectStatement would be a lot clearer. And what does dbh stand for? 
I would probably rename get to columns (and I would probably make it an array so it's easier to use).