Welcome to Librarium Online!
I'm pretty new to the whole 40K scene, and am collecting an Ork Army. I'm terrible at painting, and to be honest with work, studying etc I don't have much time for that part of the hobby...
My point - a friend of a friend just won second place in a painting comp, and said he will paint my army if I can beat him in a battle - details of which to be decided, but likely he will field a Dark Angel (Deathwing or Ravenwing) army.
Being quite new to the hobby, I've never experienced playing Dark Angels, I've played Vanilla space Marines and fare quite well.
I was wondering if any of you could help me progress my personal Waaaagggghhh! against these humy scum, and also get some of my army painted in the meantime
First off, I'd recommend you continue to give the painting a try. You don't have to be perfect to have fun with it and paint some cool units.
That aside, the Dark Angels Deathwing or Ravenwing will be like normal marines but specialized to more elite units- either terminators or bikers. Not sure what kind of army you're running. Because of the high armor save and toughness of both potential enemy armies, powerklaws are key. Neither army has the amazing long-range fire, and running a speed freek force could help catch them as they bike/teleport in. Lootas will still wound bikers on a +2. Big mobz of boyz with shootas can swamp them with enough save rolls to whittle them down, especially with big shootas for range and strength. A big mek with shokk attack gun could really shine against either. One safe bet is to mob them with big cheap squads of boyz, denying them shooting and the advantage of expensive weapons that ignore saves. Again, both are mobile armies (the terminators will either teleport in or be in a landraider) so movement is key. Either run toward them with a sea of boyz, or zoom up in wagons and trukks.