Ercokat -- For seller details do this:
Click Profiles
Sub tab Seller Details
(switch to Standard)
Enter your info...tabs on the top will tell you where you're at Payment, Shipping, About Us, etc.
After you've filled in the information, click Next, NOT Save and continue on to the next one.(If there's one you don't want to use, just leave it blank) but click NEXT.
All the way at the end, after you're done, the last screen says Name of Seller Details. Fill in a name (mine says "the usual") and click Save as New.
Done!
When you create your next listing, you will have a dropdown box showing next to the template selector...use that to pull down "the usual" (or whatever) and your Seller Details will be there.
Happy listing