Welcome to 3fc!
There's a lot of places to start, but you started the right way, by skimming the forums.
Two great places? One is the Support thread for your weight within the 20somethings forum... these are listed with the titles like "Moving out of the 180s" etc. Find the one for the 170s or 160s and just hop on in!
If you're doing any particular program, the second good place to start might be a Food or Exercise thread, depending on what you're doing. They have threads for EVERYTHING...
OOH, and don't forget about challenges... under "Chicks up for a Challenge". There are timed challenges, religious-based challenges... just about anything you can think of!
Welcome to 3fc and good luck!