Go to the Force Commander section of www.lucasarts.com
for a full breakdown of each of the 25 levels (plus hints).
As for the Kalaan mission, I think that I first collected all of the friendly stormtroopers. I initially kept everyone on the surrounding high ground to avoid the roving imperial patrols, then marched along it east and north to the TRMB. I kept the TRMB where it was (with Brenn inside) then used the stormtroopers to recruit the locals and to capture all of the imperial turrets en route (you may have guessed by now that this is a favourite tactic of mine!) If you do it right, you should have enough troops to take over all the turrets of the map, which you can then use to destroy the remaining imperial units. After this the level is pretty straightforward.