Hi Juli,
Good for you for taking charge of this! The first thing I would suggest you do is make sure you are caught up with your student loans. They get very expensive if you default. There is also a new program called IBR that can help with student loans and information is available at ibrinfo.org.
The next thing you should do is make a list of the other debts and how much you can pay on them. Start contacting the companies to see what you can do to resolve them. If you don't have enough money to pay them all in full, it's OK to offer settlements for less than the full amount. Since your credit is already damaged, you won't improve them by paying them in full. (Of course if you can pay in full, you should.)
Finally, make sure you are monitoring your credit reports so everything is reported correctly. Paying an old bill won't mean it is removed from your file, but it should be updated with a zero balance once it's paid.
Hope this helps!