There's a ton of advice on this forum for the rebuilding credit side of things, and not a lot more that I can contribute that hasn't already been said. I would reiterate to never give up, though, and that it's always ALWAYS worth a shot.
As far as the 'good personal financial habits' side of it, I think the two biggest things I learned to do were to a) pay myself first and to b) plan for the unplanned.
A) I used to try and save money by promising myself I'd stick whatever was left over at the end of the month into a savings account, and every month I'd have nothing left over. I switched to automatically transferring the money I earmarked for savings the day after my paycheck hit the bank, and like a 401K, it started adding up really quickly, and I never, ever missed it. Suddenly instead of breaking even I was netting positive each month, and mysteriously living the same lifestyle.
B) It's much harder to get out of debt than it is to stay out of debt. We all know it's better to avoid using credit cards excessively, but sometimes a financial emergency comes up. On the advice of a friend, I opened a savings account at a separate bank (to make it deliberately hard for me to get at right away) for "emergency" funds...the stuff I used to throw on a card because I had no other option. The unexpected heating bill, the car repair bill, the unexpected veterinary bill, etc. I can still pay them, but now I have the cash in the bank to pay for them right away, thus avoiding the whole credit card debt thing. You may not be able to know exactly what surprise bills will pop into existence, but you can sure as heck plan for the "generic" unplanned! This one trick kept me ahead of the game and I've taught it to everyone who will listen to me.
Starting Score: 682 EQ, 663 TU
That is so inspiring! It's reading stories like this that keep me going.