Skills Help!

Hello!
So I just switched my secondary to a monk, and I am currently playing through prophecies. What are my options for acquiring more monk skills?!

Since you're Prophecies, the first thing you should do is track down the skill quests in Ascalon and the Northern Shiverpeaks (in Kryta and the Maguuma Jungle, the skill quests aren't profession-specific so you can't go back and do them for your new secondaries). That'll save you a bit of gold at the skill trainers.

So even if I have already completed them the first time around I can go back and redo them for new monk skills?

Uh, no, unfortunately you can't afaik. However, if there are any you missed, you can do those. See, the way many skill quests in prophecies work is that their reward gives you one skill of your primary profession, and then one skill of whatever your secondary is when you accept the reward. Therefore, if you're say, a N/Me, you do the quest, switch to N/Mo and accept the reward, you'll get a necro skill and a monk skill. You won't, however, get the mesmer skill in that case. You'd have to get that via another quest (if another one has it), or buy/unlock it from a skill trainer. If you're N/Me, the same applies, but you'd get the necro and mesmer skills and have to obtain the monkstuff via other means.

This could be learned from the wiki
Purchasing a skill from a skilltrainer is the most commonly used one, along with tomes (and ofc capping elite skills). It's even easier if you unlock the skill first using balthazar faction as the skill will be available from any skilltrainer/aquired by the use of a tome.

What he was saying is now that you've become /monk, there will be some new quests available to you now that are profession-specific, which is why you were not offered them the first time through.