kazzmo, Home of Cheesebuger
is one smilie site that gives you a large selection of smilies. It also has a smilie generator that allows you to make smilies.
To find other sites, Google smilies and examine the choices given. The only word of caution I can give is to make sure you don't have to download an application in order to use the smilies. These sometimes come with more than just the application for the smilies. The site I listed is one of the many sites where you choose the smilies you want to use by copying the URL for whichever smilie.
What I've done is to copy smilie URLs from a site and paste them to a Notepad page and save it to my HD. Then I just have to access the Notepad page with those particular smilies and copy and paste the URL for the smilie I want to use. Saves always going to the site in order to get a smilie. Of course, you have to do a bit of copying and pasting to build up a library, but it's worth it.