CCNA Hexidecimal Help

Does anyone have any “mini-lessons” they would be willin to write up about how to deal with hex in the CCNA material?

What is the decimal & Hex equivalent of the Binary number 00001111… (or something like that) No matter how many times I read the section in Lammle’s Sybex book I still don’t have a solid unerstanding.

Any URLs would be appreciated. Thanks!