In my opinion, a beginner will be happier with a Whisker Biscuit rest. You can always upgrade to a drop-away later if you choose.
Arrows - size and type depends on you, your bow, and how you intend to use the arrows. Carbons are where you'll probably end up, but might not be the best for starting off. Aluminums (Easton) are always good. With 5" feathers.
Stabilizers are good things to start off with. There are tons to choose from. One that's about 5" to 6" long would be good; NAP's "ShockBlocker" is a good choice.
Release? one with a wrist strap, definitely. Either a buckle strap or the kind where the strap passes through a loop before velcro'ing back onto itself. I'm kind of partial to the TruFire Hurricane power strap.
A good budget for first-timers is somewhere slightly north of $100 for a rest, stabilizier and release. Down the road, that'll double or triple, but if it were me, I'd start building comfort and confidence and upgrade the accessories later.
The Rock is a good little bow, by the way, if you're not very tall and can't pull much weight.