Not recommended for new players. If you've never played this game it's not for you. Go experience five years of collective content. User it on your second toon though.
1. Get an instant 60 pot (from the store or a package)
2. Use Patron and a Transcendent XP pot
3. Have someone run you through Charmer's Caldera for a couple hours.
Here's a more detailed breakdown if you don't have an instant 60: