Quote Originally Posted by ozar View Post
Have you synced with the package repos before trying to use swaret to install any software?
I asked the above because you have to update your packages list before trying to install any packages, because swaret doesn't know what packages are available until you've done that. Check the HowTo in the link posted by reed9 above for some info on using it. Some of it might be a bit outdated, but some should still apply.

If you are unable to get swaret working properly, you might also want to check out slackpkg as an option. I think it's installed with Slackware by default now. If it's not installed, you can get it from the Slackware mirrors, or download it from the slackpkg website.