The first campaign exemplifies much that is good in HD2 and, unfortunately but inevitably, many of the game's sillier characteristics as well. Basically if you enjoy this campaign you'll probably like HD2 - barring a few really dumb missions and a couple of truly Godawful ones - and if you don't, you probably won't care for the rest of the game either.
In any case it serves as a good introduction, since it requires the use of most of the basic techniques. If you can get through this first campaign at Hard level without losing any men, you can feel pretty confident that you can run the rest of the game. If not, then I suggest you try again.
This campaign includes two of the most demanding missions in terms of computer resources and performance. Trees create a major framerate hit, as does snow. If your setup is marginal, you'll find out soon enough; the first mission will be almost unplayable. Turning the graphics all the way down will help, but basically you need to get a faster video card and more memory. On the other hand if the first mission runs smoothly then you should be OK for the rest of the game.
This mission supposedly takes place in northern Norway in March, 1941. A secret facility has been discovered by air reconnaissance. Your team's primary job is to penetrate, explore, and destroy the facility. Additionally, an RAF pilot has been shot down in the area; you are to rescue him. Later on, in one of those annoying add-on missions common in both HD and HD2, you have to go after some documents on an island ("iceberg") nearby.
This campaign requires a lot of shooting, so you want good marksmen. At the same time, there's a good deal of mixing it up with the bad guys, so avoid the specialist marksmen with low endurance ratings. Strength isn't terribly important because you don't have to carry mines or explosives or heavy weapons.
One man - this is very important - needs to have a high stealth rating. William Broadhurst is ideal for this. I recommend making this man your main viewpoint character, as he will have to do most of the really important work. Stealth doesn't matter for the other men in this campaign.
My own team: Broadhurst, Elliot, Lauer, and Mulholland. There are others as good as Elliot or Lauer; Mulholland, though, is invaluable. This guy is a stone killer. In any fire fight, more often than not he'll account for most of the enemy casualties.
They don't give you a very good selection. The only submachine gun available is the Sten, which wasn't introduced until considerably later. All the same, most players find they want to take one silenced Sten. (The De Lisle is too slow, and even more of an anachronism.) But it's possible to run this campaign without it, depending on which method you choose for the first mission and how fast you are with a knife on the second. For your first time, I recommend taking it, and then you can try without it if you like.
It's useful to have one sniper rifle, but again, they only offer the Springfield, which is ridiculous. It's possible to run the first mission without a sniper rifle - with care and accurate shooting - and you do get a chance to pick up scoped Mausers later on. Again, if you're new to the game go ahead and take the Springfield, but if you're more experienced, or just want a challenge, take a Lee-Enfield and give it to your best rifleman.
Whatever other weapons you choose, take a Bren. It's a pain in the ass in a lot of ways - it's so heavy the gunner can't carry much ammo, and somebody else has to pack extra clips for him; and because of incorrect modeling in HD2, he has to be lying down to shoot. But it's worth it. That thing makes such a huge difference; there are several spots in the first and third missions that can be turned from nightmare to easy meat with the Bren's firepower.
The other man can carry a Sten, and if you've already got one in the arsenal you might as well have two. Alternatively he can carry a second Enfield.
(Much of the opening action happens in terrain where the superior range of the Germans' rifles puts the short-range Stens at a disadvantage. By the time you get to close quarters where you really need a buzzgun, you'll have had a chance to pick up a couple of MP40s.)
A couple of times, just for the perverse hell of it, I armed #1 with only a pistol, and let him pick up a weapon off a stiff. It was fun but probably not a good idea for a beginner.
Backpacks for everybody, of course - except that the Bren gunner may be so loaded down he can't carry one - and helmets; never mind the pretty berets, save them for the medal ceremony afterwards. Compasses for everybody; it's very easy to get disoriented in the woods. Both large first aid kits, and a couple of small ones apiece for the remaining men. (Who gets what is up to you, but give your stealth man a big one, he's going to need it.)
One knife, definitely. Wire cutters for your lead man and it won't hurt to have somebody else carry a set. A camera; this is provided at the start. If you don't take a scoped rifle then somebody should have binoculars.
You could take few grenades, but to tell the truth I've never found a situation where they were needed. No other explosives. That's it.
Historically, this thing is hopeless. Number one, the SAS didn't even exist in March 1941; and it never did operate in Scandinavia, except at the end of the war when some SAS units were sent in to disarm surrendering German units.
The regular Commandos did operate on the Norwegian coast occasionally, but in large units. A job like this in any case would have been given to Special Operations Executive, and the team would probably been Norwegian.
The torpedo boat that comes for them is an American model, and the crew is obviously supposed to be American (they speak US English and carry American weapons), but the US was not in the war in March 1941.
The Sten gun was not issued until the summer of 1941 and the silenced version considerably later. The SAS never used the American Springfield rifle at all.
The area shown would have been out of range for a Spitfire fighter.
And why in the name of bleeding Jesus would the Germans have been running an aviation research facility in Norway - and northern Norway at that? What would be the point, seeing that they had excellent facilities of this sort - among the finest in the world - in Germany itself, far more secure from incursions and without problems of supply and support?
Then at the end it turns out that key documents relating to the mission are located at a German weather station on an iceberg! Why this would be so, what connection a weather station would have to secret aviation research in any case, is never explained.
The absurdities aren't all historical. This is supposed to be above the Arctic Circle, in March; it's snowing and there are long icicles over the doors and windows. Yet the swamp, which forms a key element in two of the missions, is not frozen! There isn't even a skin of ice over the top!
Fortunately the graphic details are rendered so well that it's not too hard to suspend disbelief; and the missions are difficult enough that you don't have much time to think about the ridiculous aspects.
All the same, it isn't the best campaign in the game. But it's fun, at its own level. The atmosphere kind of grows on you. Let's get on with it.