guide for Lord of the Rings Online posted at Ten Ton Hammer. It has a nice spreadsheet layout that covers all the different little bits involved in getting those first twenty levels. Everything is covered in the spreadsheet, including which quest was taken, location of the quest, time taken to complete quest, level attained upon finishing quest and whether it was done solo or in a group.
It took about three days of playing for about five hours each day, although Darkgolem says it could be done in a day. The only drawback to the power leveling was that he found himself without feats, crafting skill growth and about three hundred less silver in his pockets due to fast travel fees. If you don't mind any of that though, you too could be level twenty in one to three days. A good guide for any players that don't feel like staying in the starting areas too long on a repeat play-through.