Roman Empire coins

Hello, I'm trying to identify some Roman Empire coins. I'm using Krause Catalog, but I've seen that coins are catalogued with differets codes than used by Krause. In fact no-one is catalogued using Krause code.
Which catalog do you use to identify them, and why??

The net can be good for this sort of stuff try wildwinds - it's quite an impressive site.

You could also try posting pics on Numista and asking if anyone recognises them.

here's a good site that might help

http://www.dirtyoldcoins.com/Roman-Coins.html

Thank you for the answer.
I'm going to visit those sites.