Never tanked before, wanted to try. It seems enjoyable and I wanted to get other opinions. How could I be a good tank? Is there a specific race that excels as a tank better than others?

Thinking of being:
Blood Elf Paladin or Rogue
Night Elf Rogue
Tauren Warrior

Any suggestions? Thank you

I have a Blood Elf and he does well, it mostly falls to having good weapons, armour and skills. Tanks have skills that generate lots of aggro, and some can shield others (which increases your aggro and lowers theirs.

Check the link for plenty on tank info.

Well, first of all, I feel I must point out that rogues are not a tank class.

Choosing between warriors and paladins is a bit of a toss-up. They both make good tanks, but they're good at different things. A warrior tank is better than a paladin at tanking a single enemy, such as the final boss of a dungeon or raid. A paladin, on the other hand, has an easier time with large groups of enemies, and is easier to level up with solo, due to their ability to self-heal. Both are good with single targets and groups, mind you. They just have different specialties.

Since you mentioned rogues however, I'll mention druids. A druid in bear form is worse than a warrior at tanking groups of enemies, but is functionally very similar to a warrior tank in play style and feel. Shifting to cat form, a druid becomes DPS, and is very rogue-like in play style and feel. With dual spec, a druid can simultaneously be melee DPS, tank and healer, which makes for short queue times no matter what is in short supply in the dungeon finder at that particular moment.

Race doesn't matter all that much. But tauren do get a bonus to health, which, while it isn't very large, does make a small difference.

I personally like my warrior tank more than my pally, so if you decide to go tank I would suggest the warrior over the paladin. Rogue is probably my favorite class though, if you're looking for some fun dps / ganks. I went subtlety and never went back.