I learned the game as the Gaians and think they're very beginner friendly. It surprises me nobody mentioned them. They only lack in the growth (as in food needed to grow, food production is good) and military department (-1 morale, as if you feel that when you get extra minds worms to fill in your military).
Best beginners factions: Pravin Lal, Chairman Yang, Lady Deirdre. I already know that as a 'noob'.
I suppose this may be less true at lower difficulty levels, but Yang actually requires a great deal of skill to pilot due to his poor economic performance, especially in the early game. Hive players are likely to expand too fast and stall out without a strong understanding of the game's mechanics.