Yeah, you have a LOT to learn before you go on to becoming a punk-ass rogue running around harassing lowbies. If you get a friend or 2 to play with you a couple hours a night, you would be friggin' amazed at how fast you can level. 2 hours a night and a little more on the weekends and you'll probably be at 60 in 2 months. Instancing is your friend. You make good money, get good drops and lots of exp. You'll want to start picking up blue items ASAP from instances. Don't forget quests, though. Especially class-specific quests, you'll get fabulous rewards for those. Pick herbalism and alchemy for professions, they seem to bring in the most money per effort. (Everybody likes potions). You can get other professions later for your other characters to cover more bases, but you've got to get yourself some cash first and foremost.
I started out a Paladin and ran with 2 of my friends every other night or so. Let me tell you, Pally/Priest/Warlock is a KILLER combo. Grabbing 2 more groupies for an instance is pretty easy. Furthermore, keep searching for a guild that is full of people who like to run instances. A couple months ago I got into Zahir (Skullcrusher server, alliance side) and the people in that guild have been SPECTACULAR. When you use guildies to fill up your instance group you get to run with people that you can trust and who you KNOW are good (read: won't bail on you halfway through an instance unless their mother is on fire). Typically they will level the same speed as you, so you get to run with familiar people all through your levels if you keep up. It just makes your entire situation better.
Hit up thottbot.com and wowwiki.com for help with finding quest stuff and deciding which instances to hit so that you get the best equipment possible. Also, you can get some pretty spectacular equipment if you do the PVP battlegrounds, too.
The secret to success as a lowbie is to run with a friend or 2. Learn about the game, too. Make sure to spec your character's talent tree according to your style. As far as instancing, my BIGGEST nugget of advice is to DO YOUR JOB. Focus on doing what you are supposed to do. Be the best tank possible if you are tanking, be the best healer possible if you are healing, and RACK up the damage if you are a rogue. Your job is straight-up DPS and sapping. Believe me when I tell you, people will remember you if you do a great job and you have good manners. Good players have a tendency to find other good players and stick together.
--long winded, but I hope I helped.