MathBits has a really cool online presentation on how to use Algebra Tiles. The presentation goes through how to make the tiles, then shows how to add, subtract, multiply and divide before moving on to polynomials. Here is the link for the main MathBits Algebra Tiles page. From here, you can print extra copies of the algebra tiles, read an introduction, or open the PowerPoint presentation.
And here is a direct link to the PowerPoint presentation.
Here are a couple videos to help you out, if you're having trouble:
Wondering how Algebra Tiles work? Introduction to Algebra Tiles
Want to know more about Algebra in general? Here's a playlist from Khan Academy.
Learning to multiply positive and negative integers? There's a video for that. You need to try it using algebra tiles though. :)
Learn more about how to multiply polynomials.
Learn more about dividing polynomials.