As World of Warcraft continues to expand larger and larger, with the level cap increasing over time, it's becoming more and more difficult for people to have multiple characters at max level. Everyone would like to have characters of all classes at level cap, but it is terribly time consuming to be able to do that.
Luckily, Blizzard has introduced, with the Cataclysm expansion, a new type of item to help players level their alts quicker and easier than ever before. They are called Bind on Account items, or Heirlooms. In order to have access to get Heirlooms, you must already have at least one level 85 character, for the most part.
Power and Extra Experience
There are 2 awesome benefits of getting and using Heirloom items. The first benefit is they scale to your level. So, as you gain levels, the Heirloom item stats (armor, damage, etc) increase as well. This is really cool because it makes it unnecessary to upgrade most of your gear. Heirlooms have good stats, armor, and damage for your current level, so they keep you powerful and able to do quests quickly, which is a huge plus when trying to level up some alt characters.
The second, and probably most important, benefit is that some Heirlooms increase the experience points you gain from killing mobs and turning in quests by 10%. If you have 3 Heirloom pieces that give a 10% experience boost each, that's a total of a 30% experience boost for your character while leveling to level 80. So, if it usually takes you 6 months total, real time, to level your alts, you could level that same character in about 4 months total. Just having Heirlooms could save you 2 months of your time! That's pretty amazing, if you ask me.
Getting Your Own Heirlooms
The most popular way of getting Heirlooms, hands down, is by doing dailies. Getting a full set of heirlooms can be done pretty quickly by doing dailies, if you know what you're doing. The whole point of heirloom items is to save you time. So, not only do you want to save time after you get your Heirlooms, but you should also look into saving time while in the process of getting Heirloom items.
The way to do that is with an optimized route of all the dailies you need to do in order to get the items to trade in for Heirlooms. Obviously, you can figure out your own path for doing this, but if you're like me, you'll want a guide written by professional gamers for the sole purpose of getting dailies done quickly.
There is a certain guide I use for all my dailies needs. It's called X-Elerated Warcraft Guides. In their guide, they show you step-by-step how to get Heirloom items. As a bonus, they walk you through speed runs for making gold with dailies, as well as getting your Crusader title, which is needed to buy Heirlooms if you want to be able to buy them by doing dailies alone. If you want to get Heirlooms, gold, and your Crusader title fast, I highly recommend picking up a copy of the X-Elerated guides. Good luck!