I'm beginning my credit repair journey with a score of about 570. It is this low due to defaulted student loans (huge impact), medical bills, and stuff that belongs to my parents that isn't mine (another huge impact).
I'll keep you updated as I try to have misleading and untrue items removed from my credit report and see my score rise.
Also, I'm in a rehabilitation program for my student loans. When the program is completed, my loans will go back to "normal" status and not show negatively on my credit report anymore. I have to wait for this to happen and pay on-time, but when it happens, it will be an automatic huge boost.