Healer looking to try out DRK, any advice?

Hey everyone, so I'm lvl 60 for all 3 healers and it's all I play and feel I'm pretty strong at it. Got bored the other night so tried our DRK which is actually pretty fun. I notice though all the cross class skills are from the other 2 tanks. So I leveled Gladiator and Marauder to 15 to unlock a bunch of them and my thought was I'd get Gladiator to 15 (since I like it more) and then level it to 30 via dungeons to get practice. I was doing Sashtasha etc with DRK to learn, but might as well get more EXP leveling one of the other tanks. Would that generally be the best way to do this?

Although it's not truly essential until you encounter something with a tank swap mechanic, you'll need to take GLD to 22 to get provoke. However, once you need it, it's a "wipe if you don't have it" kind of deal, so if you like tanking, do pick it up. After that, play your tank of choice to your heart's content.

If you plan on playing DRK in any endgame content, I would level PLD to 34 to get all of the cross class skills, and MRD to 26 for the same reason.

As far as other jobs to level that may make the experience easier, having healer exp definitely gives you a good feel for mana-management, while leveling DRG to get used to mashing a lot of buttons or NIN/MNK to get used to attack speed increases can also help you build the skillset you need to be good at DRK. DRK borrows a lot of the pacing and button-mashiness of melee DPS jobs much more so than the other tanks so that can help, if you don't want to be learning that and the playstyle of tanking in general at the same time. Its a challenging tank to play well, but pretty rewarding.

Have fun >=]

What the other guys have said, I can't remember to much of DRK as i haven't played it since i got my DRK mount to be honest,

If this is gonna be your first tank, Don't get discouraged by people who like to bash new tanks. DRK Is very reliant on MP and MP management will be key, But as a healer i'm sure you're already familiar with that so i have no doubt you'll do fine there!
As you go on just get comfortable with your skills and eventually(Personal opinion) swap out VIT for STR as you feel comfortable with your current content.

Early dungeons will get you settled in quite a bit, gets you used to holding hate on a group of mobs and just do your thing, Main thing is to have fun with the class and see yourself improve!

Thanks everyone appreciate it! Yes, having a think skin (or should I say stone skin? lame joke :D) is necessary to be a tank which I might have issues with haha. Tanking is definitely hard, or at least need to know your stuff but I think it should be fine. I will admit, there's something pretty thrilling about being the person that rushes in and pulls something. I think I'll do as suggested, level PLD to 34 or so as I definitely saw I needed Provoke, so figure since I'm doing level 15-30 dungeons anyway (as I don't want to start DRK right at Haukke Manor since I need practice), I might as well use PLD or whatever on them to get some roulette bonus as well as more EXP vs the level sync'd little bit I'd get from playing those as DRK.