Guide for Level 3 Soloing?

I'm ready to give soloing a shot, and I'm wondering if anyone has made a basic guide for soloing level 3 raids?

In particular, I'm interested in the best counters based on the boss' moveset.

And I'm wondering if it's better to power up the pokes I have to max, or work on powering up duplicates of the best counters to level 30.