If what you downloaded is the source code release then you need a C compiler to compile and install it (yea, like you need GCC to compile GCC).
What you should do is get the binary release from your distro vendor, for Suse you can get RPMs for GCC here:
Install all of gcc-* packages if you're not sure.
Also see if you can find the RPM for that particular library, because RPMs check the RPM databse for dependencies, not your actual filesystem, so what's gonna happen is your Gaim RPM will still complain about the missing library, even if its there and you installed it from the source.
Though you can get away with it by doing --nodeps, this is genereally not a good idea.
Here's a good site to look for RPMs:
If you can't find the particular RPM for your distro, before you download the one available on some other distro try to find the source RPM then compile it(as easy as "rpmbuild --rebuild <package.src.rpm>". This way you have a better chance of avoiding broken dependencies and such. Or alternatively you can create your own RPMs from the source using something like "checkinstall" or even "rpmbuild" if a .spec file exist.