Bluebear Jeff asked about Volley & Bayonet for the WSS. That's all I use. I've tried the rest and found them wanting, getting too much into the minutae that I used to love, and am now impatient with.
A few notes as an overview: V&B is top down. A regiment is on a 3"x1.5" rectangle, a brigade on a 3"x3" square. You, as Generalissimo, do not care about all of the nitty-gritty going on at the battalion level. You could care less whether they reload in 9 motions, or 12; there are sergeants to handle that. You don't have to order them into square if charged by horse, you have junior and field officers to do that. Turns are one hour. A lot can happen in that time.
There are differences between the combat systems in the WSS, and it is accounted for. There's modern drill, and early muskets, or Early Firelock Drill. The former, when stationary, shoots with 4 dice; the latter, when stationary, shoots with 3. You hit with 6's. Foot units are a little stiff for maneuvering, and if you can bring multiple units against one, you get to throw a whole lot of dice. The maneuver element is the horse. They don't have the facing change restrictions of the foot, and so they are the part of your army that can turn the tide and win the battle.
Artillery is useful to have because, in part, they cause morale checks on the enemy. But they aren't absolutely required.
Now as for the differences between 1st and 2nd... 2nd edition has the glitches fixed that were developed through a lot of playing of 1. There weren't many, but they always seemed to crop up at the most critical times. The rules were originally set for the 19th Century, but people with a great deal of knowledge gave critical feedback for the 18th Century, and one gamer did the League of Augsburg (1689-1697) variant.
A good game of V&B in the WSS can be had with 1st edition. That said, the refinements in the 2nd edition make them worth the money.