Typical party setup for me at lvl61 is:
whm/smn (healing)
blm/smn (nuking)
brd/whm or rdm/blm (crack dealer.... errr refresh)
pld/war or nin/war (tanking)
rng/nin (damage) x 2 if possible
thf/nin, thf/war, drk/war,mnk/war, drg/war(bleh) or any other DD combo here
post 65 light skillchains rule the damage world and rangers and monks really gain value with sidewinder/slugshot and dragonkick! ex: sidewinder for 600dmg + dragonkick for 600dmg = light SC for 800dmg + any applicable MB (most likely Banish III after update) for 200-400dmg
I have a good friend who is playing monk and will hit 69 today and you just have to make it through the tough low and mid-lvl's. What I've found is any job can have value to a party but there will be times when your job is just not good for certain stretches and will not be picked up as often for parties. Example is thf before he gets Sneak Attack at 15 then from 25-30 is pretty bad until you get viper bite at 30 and at 33 you get Trick Attack (transfer massive hate to the tank) and SA TA VB is wicked deadly!
Hope my info is helping you out and not confusing you too much haha. I think the greatest advice I can give you is try to stick to 1 job and take it up as high as you can tolerate. If you find a dry run, lvl something else for a week or two and come back to your main and you will find all the people you were leveling with have moved on and you can get parties with a fresh batch of people. This has worked for me in stretches of no party invites in the past.
Happy hunting!