SoA = Stop Opp Ability
SoB = Stop Opp Bonus
(R), (U), (C) = Rare, Uncommon, Common. You can safely ignore this.
If you play Rescue, you really should play 8 of them since their bonus uses Support. The +1 damage from Timber isn't generally worth the -3 attack, especially since Timber himself has poor stats for a 5*.
Take a look at the Rescue cards and see which ones catch your fancy. Read the reviews to get a general idea of their strengths and weaknesses, but ultimately you should pick a deck to fit your personal style. Aside from acacao's suggestions, lots of other cheap Rescue cards are playable, like Wesley, Joana, Krash, Tanner and Suzie.
Take your time, experiment, and have fun!