Well, if I am reading your question correctly you want to save Titanium (the program not just the backups) to your SD card. And for that, you'll need Apps2SD (A2SD). I ain't sure how to get this on a stock phone, I have the Icarus ROM (the operating system) and it came with it already installed. So Google search or serch on here for A2SD and you should be able to find what you need. If not, post back here but please be more specific in your questions next time. "Can't figure out how to use my sd card" is quite vague, don't ya think? At first I though you didn't know where to insert it into the phone.