The "Crusader" title, which is a title reward for the achievement of "Exalted Argent Champion of the Horde/Alliance", requires one to complete almost all of the achievements associated with the Argent Tournament. It is essential to be able to buy some of the new heirloom gears available in patch 3.2 through means of Champion Seals, even though these can also be bought by purely doing some heroic instances and spending "Emblems of Heroism". To be able to show off the "Crusader" title in WoW, one would have to hit exalted status with all of the home factions, be it horde or alliance. And not to forget, the amount of time spent jousting and doing dailies to become a champion, (via the Argent Tournament) of every Horde or Alliance city faction. All this will also bag you some other titles and achievements along the way.
This guide will mainly take you through the "Horde" version of the Crusader title and how to go about getting it for yourself efficiently and systematically without putting in too much effort. So without further loss of time let's get right down to business.