Ok... so in a 2.5 hr. session we got through three encounters (keep in mind this is our first combat, outside of my limited experience here) I'll make 2 posts, 1 detailing the combats, and 2 with my thoughts.
Combat #1: Attempted ambush by a group of kobolds, including two dragonshields (fighter-types), 1 artillery, 1 leader (shaman), and 4 minions (1 hp each)
The elven ranger managed to roll a Natural 20 (this becomes a theme with him...) on his Perception rolls (which I like more than spot & listen as it speeds up the game slightly, I require each player roll one at a time, as I had some incidences of dice nudging, fudging by one of the players...

).
The group (a ranger, warlock, and paladin) weren't surprised and the two strikers began lobbing ranged attacks at the enemies. The paladin charged forward to provide cover. They started off blowing out their encounter powers and destroyed the artillery kobold and damaging the shaman. The paladin was wielding a glaive, giving her reach and she used it to great effect (even though it doesn't threaten). The Paladin player struggled with why the at-will attacks were better than her basic attack, despite offering a minor bonus (in this case a -3 to foes attack rolls), but she quickly got the hang of things. They mowed through them pretty quick, despite the supposedly challenging battle.
We took a break, while I put the boys to bed, and they said that they found it interesting so far, but the warlock was upset because he kept missing...I recommended he try the powers that attack different defences (he kept using a power that hit against the kobolds Reflex)
Combat #2:
This combat was just outside the kobold lair, behind a waterfall (and on a cliff) so the group was stealthy (except the Paladin) and they snuck to within striking distance. Again, they opened up with their encounter powers (and
2 Natural 20's in a row by the ranger) taking out the lookouts right next to the entrance.
The ranger then decided to try his blades out and the Warlock used his daily power during this encounter (to great effect) and used his ability to curse more often, gaining extra damage and temp. HP as a result. As well the Paladin fell more into her role and began marking the enemies, causing them to take damage if they avoided her.
***This point I was nervous about bookkeeping enemy statuses, in this case there were marked, cursed, on fire, and one was the ranger's quarry, but it was pretty easy, I keep track of enemy hp using Excel, so I just put a note next to them ***
Again, they were working pretty well together, but then the strikers stopped moving and were just hitting.... that's when things got bad... the ranger got ganged up on by a trio of kobolds (2 minions and 1 rogue) and very quickly fell unconscious (I also rolled 18's pretty consistenly for a while). Eventually he made his death save (Nat 20 again...

... this time I checked the dice...just in case it was one of those cheating dice... but it was good), but it was tense as he failed it twice first and once more would've led to his death.
Combat 3: Inside the lair
This was the most difficult encounter and the group felt it as terrain came into great effect, with some pits, side entrances only small creatures could fit into. The group lacked any powers that could push enemies, so the terrain was pretty ineffectual and the last enemy had over 100hp. The Paladin hit him with his daily power and took out 1/4 of his hp, but after that and the encounter powers were done it fell into their at wills.
The ranger continued his two attacks, the warlock used the same at-will, and the paladin the same...they won the day after a bit, and the paladin going unconscious.