Being a hybrid class, Paladins have several great talent trees to work with. You can tank, heal, or provide melee DPS in any group. Through the three talent trees you are able to tailor your ability to fit your requirements. The tree that I am most fond of though is the Protection tree which we'll be taking a more detailed look at here.
While looking at the paladin tanking builds it is important to understand a few things on how tanks work currently. In the current game tanks are able to generate huge amounts of threat due to the way that Vindication scales our attack power as we gear up. This means that many of the threat generating abilities that tanks can gain are not strictly required unless the DPS in your group or raid constantly jumps on a boss full out at the same time you do. If they give you even a few seconds, there is almost no reason for additional threat.