I'd recommend you start with the Wiki and peruse most of the topics.
There are especially a couple of topics for beginners that will be useful to you, especially those in the BitComet Tutorial and BitComet User Interface sections, as well as the first section of the FAQ (Understanding BitComet).
BitTorrent is pretty different from the eDonkey protocol and the general logic behind the BitTorrent clients is rather non-intuitive until you read and comprehend it a bit.
Before you wrap your mind around a few basics you'll be fumbling in the dark, mostly, if you try to compare it to other sharing networks so, I'll say "happy reading", wherever you may choose to do it.
P.S. as a bonus you will find out that BitComet integrates the eMule client as a plugin, in order to perform cross-protocol downloads when the same file is available on both networks. But that's already an advanced topic that you need not bother with at present time.