2 Sites to check your speed are -
http://www.speedtest.net which is a fairly good benchmark speed test...
The other one, is worthwhile when you speak with AOL...
http://speedtester.bt.com - when you run this one, make notes of everything you see including the time you run the test. Run it from a computer that is wired to your router,
not wireless and make a note of the time. Run the test 3 times, at least 3 hours apart from each test, making the notes of each test.
With the 2nd of the 2 tests, you can tell AOL exactly what was reported to you, but, they can get information from it too, with regards to any possible errors.
The other thing to do is to make a note of when your connection appears slower (and test accordingly)...
I use Orange and they reckon that in my case (I am supposed to get 3mb connection, but, suggest that a 2mb connection is acceptable) 2/3rd of my speed is about right (I don't)...
I personally see download speeds of 100KB/s per 1Mb connection (less a bit) as a close guide as to what to expect (in my case I get 250 - 275KB/s).
Ping speed should be as low as possible (I would again expect 50-80ms)...