Sagequeen recently released part seven of her excellent Mass Effect 2 Adept class guide video series, which takes an in-depth look at each of the Adept's biotic abilities, discussing choices, usage, combos, and nuances. Even if you're not really into playing a caster-oriented Shepard, this guide includes some well-presented information applicable to biotic-oriented squad mates.
Unlike most guides that simply tell you what the author prefers, Sagequeen lays it out on the table for you, instructing you about benefits and downsides, allowing you to make your own informed decisions based on the style of play you prefer. For Mass Effect, video guides seem to be more effective than the written word at showing you how the game works.
I've found that these particular three videos, clocking in a total duration of 37:38, form a solid backbone for developing your own adept build (note: ignore Youtube's attribution of this playlist to us):
Check out the rest of the eight-part Adept guide for more about equipment (guns, ammo, and armor) and other gameplay considerations!