can't add a font

What are you trying to put where? Usually one installs fonts through package manager, in all repositories there are over five hundred font packages available.

If you really want to put some file into a system directory you should use terminal and "sudo cp".

i was trying to get fiesty fawn to mimic osx tiger. i was trying to add the font that is used. i had found a good osx icon theme but don't remember where i found it at.

If you're using gnome (ubuntu's default, not kubuntu or xubuntu), you should be able to just do the following:
- Places-->whatever
- Go to-->Place, type "fonts://"
- drag and drop a file there (some font file, .ttf for example)

This doesn't work for you? What type of font (file extension) do you have?

Sorry, Go-->Location...

You can also reach the same folder through System-->Appearance-->Fonts-->Details-->Go to Fonts Folder.

i did this ,but when i try to drag and drop the font i get a message that says i don't have permission and am not the administrator, witch is root i believe.

Thanks Wrwrwr, that solved my question.