Um... play Vanilla for starters, and play offline at first. Get a handle of the game and what you're supposed to be doing. Also, the wiki is your best friend: http://www.minecraftwiki.net/wiki/Minecraft_Wiki

As for mods, the only mod I would suggest starting out is Optifine, which lets you customize a ton of stuff to get some performance boosts, and also gives you lots of extra tidbits if you're into texture packs(high res support, and other things that texture packs can take advantage of to look better, like connected textures). However this isn't really necessary if Minecraft runs well for you and you don't use texture packs.

Um... honestly I wouldn't suggest a server for a new player. They're full of drama, it's possible to be griefed and so on... and more importantly servers tend to get wiped/start over. You want your first experiences to be something a little more predictable and stable. I say find a few close friends who you can trust and possibly play games with, and one of you host a private server you and some friends can play on together. It's way more fun that way. Then maybe go onto public servers.