DNC and RDM are great choices all the way to 80 for learning how to DPS.

DRG and MCH require a lot of doubleweaving to do them well, but they're fairly easy til 60+.

Every DPS job without exception requires you to read tooltips and know what your abilities do.

A major problem with tooltips is that they don't clearly communicate to players (who aren't mathematicians) which abilities and spells are the most crucial, or why. So it is quite often necessary to look up explanations online from other players about how various abilities work and when to use them.

Unfortunately the game does not offer any explicit tutorials.