Newbie here - Question about MP

[Tenebrion]

Hi, I first picked up Dominions 3 about a month ago, and have been obsessed with it ever since. Only recently have I decided to put forth the effort into playing the game online against other opponents, but I've run into a few problems. I have a few simple questions, and hopefully someone can provide a few simple answers.

1. How do I find a multiplayer game to join?
2. How do I join a multiplayer game?
3. Are there any mods, tools, programs, chat channels, or websites that I need to use, or should use?
4. What kind of game models are there? Can I expect to have access to games that take place all in one sitting, over the period of a week, or over the span of months?
5. What's the most common multiplayer game format and timespan?

Thanks in advance.