Which server should I use for CoH?
Freedom is the original server. It has the highest population, so you're most likely to find teams. People who play on other servers will also tell you it has the highest population of morons.
Exalted is VIP (paying people) only, but it's very popular since it just went live.
Virtue is quite populous as well. It's the designated server for people who actually want to role-play, though those people mostly keep to themselves.
Union is an English language EU server with a high population.
The least populous servers are Pinnacle, Guardian and Protector I think. Everything else is someplace in the middle. I generally play on Liberty.
For a starting character, I'd suggest a Scrapper or Brute since they're sturdy, high-damage types, or a Dominator if you'd rather have a challenge. Blasters die too much, Stalkers compare poorly to other melee types and most of the other choices are less friendly to new players.
Play Hero-side first. There's an extended tutorial now that's started from the contact Twinshot which runs through most of the game's non-combat mechanics. I'd recommend that as well.
A lot of veterans will run "sewer teams" to take them from level 2 - 15 in around 90 minutes. That's pretty chaotic and might not be the best experience for a new player.