To give you a rough idea, here's a US M4's crew standing next to it's equipment: http://s104.photobucket.com/user/Von_poop/media/album%202/Shermancrew.jpg.html

Here's someone recounting his experience fighting in WW2 as a tank crewman who trained on an M4 Sherman only to discover he was going to be fighting in an M3 Stuart. With no turret. http://www.bbc.co.uk/history/ww2peopleswar/stories/03/a2310003.shtml

Furthermore, while I'd call into question the accuracy of the physical game, World of Tanks has a running feature where they have one of their military advisers climb around on tanks and show you around called "Inside the Hatch." https://www.youtube.com/user/TheChieftainWoT

Most tanks have machine guns that can essentially be popped off the tank and brought around. While a gun mounted to the top of the turret is usually what everyone thinks of, tanks typically had additional ports on the sides and front of the tank. Not all of these could simply be detached though. Some tanks also had a machine gun port mounted to the back of the turret.

Crews were typically equipped with an odd array of small arms. German tanks mid-war made use of pistol ports but as the war dragged on they became less common to cut back on the cost of manufacturing tanks. No one else really made use of pistol ports but the crews were typically armed with something so that they weren't completely naked if their tank wasn't operational. US tank crews seemed to have had Thompson SMGs standard, but I can't find anything that confirms this, and it strikes me as a bit lavish- Thompsons were a bit pricy to manufacture.

Early, crude tanks- particularly for the Soviets- often made use of primitive transmission systems that required you use a mallet to hit the gears into place. The point to this was that it was incredibly inexpensive to manufacture, and used the same transmission that many farm tractors from this era would have had. Not many Soviet soldiers had any experience driving a car per say, but if you happened to work on a farm you at some point probably had to learn how to work the tractor.

A fair amount of parts and tools were kept inside the tank. While something as involved as overhauling an engine would typically require specialized equipment and time in a shop, crews were expected- typically- to know how to perform repairs on the mechanics of the tank, and take care of the tread system. But sometimes you can't help it when you're German, and your tank weighs 70 tons. There's only so much a crew can do before a specialized piece of equipment needs to be brought in.

The electronics for tanks is something I'm admittedly fuzzy on. I know they were notorious for being a bit unreliable- many countries took to wrapping the wiring in paper or something similar because rubber was simply too important for other applications to be using it to insulate wires. So far as what'd happen if, say, a radio was wrecked, is a bit beyond me. Because of the simplicity of the radios from the time I have to assume they'd be repaired if at all possible, but its honestly something I'm not sure about, and to the best of my knowledge no one would want to send someone with that kind of talent in a tank out to war.

Tanks would be stocked with munitions for both the main gun and machine guns. Because of the fragile nature of the munitions they were stored on racks. Some who were a bit more foolish would take to stuffing additional rounds anywhere they'd fit which would cause problems- particularly for US crews- when those rounds would be struck in combat and fire inside the tank. That's not a good thing and was the main culprit behind the US M4 Sherman gaining a reputation for bursting into flames.

So far as the actual soldiers they had their fatigues, if it involved cold weather they'd have a jacket, they had helmets and generally some form of goggles. And a belt.