The tutorials on the amfphp website are not bad, if a little fast. Try "installing and testing part 1" -- it claims to show you how to set up amfphp in 7 minutes. Sephiroth, in addition to the php serializer class, has a whole section of tutorials on amfphp.

Like I said before, amfphp is pretty heavy-duty, but once you learn it, you'll have a lot more power at your disposal.

If you just want the variables to go through and want it done fast, look at the link silentweed posted. It doesn't get much faster than that.