A few days ago I picked up two legion core sets, Leia, rebel super commandos and rebel specialists. I have been having trouble coming up with a descent (and powerful) army with what I have. Do you guys know how to bring the best out of this selection and if not how so? I am a new player so the information would be very useful!

You've got the goods, already for Rebels. Leia and Luke are still the best Rebel commanders.

Luke Skywalker (160 + 20 = 180)
--Force Reflexes (10), Force Push (10)

Leia Organa (90 + 0 = 90)

Rebel Troopers (40 + 41 = 81)
--Z-6 Trooper (22), Rebel Officer Upgrade (19)

Rebel Troopers (40 + 22 = 62)
--Z-6 Trooper (22)

Rebel Troopers (40 + 22 = 62)
--Z-6 Trooper (22)

Rebel Troopers (40 + 22 = 62)
--Z-6 Trooper (22)

Rebel Commandos (60 + 32 = 92)
--DH-447 Sniper (28), Duck and Cover (4)

AT-RT (55 + 30 = 85)
--HQ Uplink (10), AT-RT Rotary Blaster (20)

AT-RT (55 + 30 = 85)
--HQ Uplink (10), AT-RT Rotary Blaster (20)