This might help you for tactics:http://www.simhq.com/_land2/land_062a.html
You can also hold ctrl and click on enemy targets to set your gunner's target, which is usually what I do in the M60.
1. Shoot first, if you won't be able to shoot first, don't go there.
2. Recon using infantry, to help you do point one while on the offensive, helps to know where the enemy are before you arrive. I like to keep some infantry OPs around my tanks on the defensive and infantry screening my flanks and reconing ahead on the offensive. Mechanized recon teams in APCs are great on the offensive, the APCs can get them close and then you can advance on foot sans APC. As Sun Tsu says 'Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win', I like to find the enemy first and flank their attack or carefully pick off their defense if at all possible. You can't always do it, but if you flank enemy armor on the move or such, it's a turkey shoot. Just try not to roll full speed into the unknown or not know whats on your flanks.
3. There are hull down spots, but they may not be obvious. Ditches work, but a shallow 2 meter rise over 100m can work too. It only takes a slight ripple in the terrain to hide a tank. But yeah, they are hard to find.
4. Concentrate your tanks to a degree, numbers help, but keep them close enough to support, but not too close. A few covering the flanks is handy.