see the >>'s in the spoilered/quoted text below. Basic info (including spoilerish material, but fairly clean) for the ones that didn't already have enough.
Originally Posted by UltimateHoboW/Shotgun
– Daario Naharis: A confident and seductive warrior.
>> Leader of a mercenary army. Plays a significant part in Dany's storyline through B5.
– Jojen Reed; Meera Reed: A teenage brother and sister duo with special insights.
>> Protectors/teachers of Bran after they flee Winterfell (should have been in season 2 if they stuck 100% to the books).
– Olenna Redwyne (The Queen of Thorns): Margaery Tyrell’s sharp-witted grandmother.
>> Takes Sansa "under her wing" to an extent. Is my favorite non main character, particularly for her personality and actions =) You'll understand after S3.
– Beric Dondarrion: A skilled knight who is the leader of the outlaw group Brotherhood Without Banners.
>> He's the leader of the group of men sent by Eddard to arrest Gregor Clegane in S1. Currently this group is an outlaw group that we see Tywin order hunted down in S2 while he's at Harrenhall. The group has a small but very significant part (which crosses paths with a couple major characters in, interesting, ways) to play in B3 and B4.
– Thoros of Myr: A red priest who follows the same religion as Melisandre.
>> Part of Beric Dondarrion's outlaws.
– Tormund Giantsbane: A Wildling raider.
>> One of Mance Raynor's "right hand men"
) Can somebody give me some 411 on these guys. Thanks!