I would start by just rooting, getting to know why you would root and how it can help you with rooting enabling you to do other things and what apps require root and why.
Rooting does not harm your phone.
Then my next step would be installing clockworkmod, getting to know clockworkmod, create backup & restore points, copying the contents of the OSF internal sd card to your PC, then do a restore from all that, learn the file structure of what is what on your internal sd card, what goes where.
Install Titanium Backup (Pro if you can), backup all your apps & data to the sd card, again copy the contents of the sd card to your PC, see the contents - learn it.
Once you are happy & familiar with all that - you are now ready for a rom of your choice. If it all goes wrong (it normally doesn't - but we have now covered all that), you can always restore to what you had working beforehand.
We have a rooting forum here as a sub forum - All things root, have a read round there too on how & why. And read this thread before anything else
http://androidforums.com/san-franci...updated-how-install-custom-rom-zte-blade.html
GL