TC35 GSM development board (from eBay) - Confused

So I just bought, and received this (from eBay):

Here is the schematic:

This description states that it can do (RS-232/TTL) - before I plug in to this and blow my arduino or the card up, this board has a MAX232 on it, can I use TTL (tx/rx?)

I have hard times with schematics, as I am just learning, could someone take a look and see if I can just use TTL?

Update: So I read up, and I know what the MAX232 chip does. I want to use TTL, so I suppose what I want to know, is where can I bypass that chip and go straight to TTL? (if someone could help me out and explain, as I don't want to blow this thing up)

One side of the MAX323 is RS232 (+/-12V) and the other side is TTL. You can tap into the TTL level signals. The schematic you pointed to shows JP2 being a perfect place to tie into the TTL level signals before they go to the MAX232.