2 whole hours between posts...
Well, in between posting, you could have looked in the dedicated Ringtones, Themes and Wallpapers forum, where these questions have been asked and answered literally hundreds of times. Even today they were answered.
In any event, to get pics from your PC to your BB you can mail them to yourself. Then save them.
To get ringtones from your PC to your BB, you must first upload them to a web site like www.coolservice.dk
and then download them using the BB browser. There are loads of websites with ringtones for the 7100t.
Good luck and welcome.