Gundark said:
What's it like gaming over the internet.
Gaming over the internet has its benefits and its drawbacks.
The biggest drawback is the lack of human interaction. Watching your buddy piling up dice because he is lost about what's going on in the game is a classic moment. Sharing pizza and talking nonsense is also a staple you'll not have. Bonding, I guess, is the word that best describes what I'm trying to say. Bonding is slow online, and sometimes nonexistent.
The biggest benefit is (in my experience) the heightened roleplaying; it's just easier to roleplay all the time when you only have to type. Usually shy people, those who wouldn't roleplay in a face-to-face game, are fine roleplaying online.
Another benefit is flexible scheduling; most of the time you can play that extra hour you need to wrap up the adventure as everybody is home anyway. No driving time, that's one more hour of gaming.
All in all, if you ask me, if you can choose between people around a table or online gaming, go with the people. Human interaction trumps all.
If you are still set on online gaming, let me give you a tip from my experience: do not use voice communication. I've tried it, it's terrible. When we talk, unless you are a professional voice artist, we tend to rely on other physical cues to convey and understand the meaning of what is being said. Without those you don't realize that the other person hasn't finished talking, for example, and people start talking on top of each other. When that happens enough times, tempers begin to flare.
Also, specially for people who don't do voices when roleplaying, you don't know if what's being said is in-character or out-of-character; an in-character discussion can be misinterpreted and quickly escalate into an actual player dispute. In person you might get a face or some other cue, like lifting a pencil; nuances you pick up without noticing.
All that said, it can be awesome! With the right people and the right attitude (i.e., no cheaters) the game can be magical. If you are a regular reader (as in book reader), playing online brings more of your imagination to play, as the act of reading the action and roleplaying will set your mind in the same state as when you are reading a book.
To finish up this long post, I play with my own software

, which you are invited to try out. The link is in my sig. Enjoy!