Hello some help with triggers

Hello, I am tring to make a modern combat like map and have decided on a way of income that requires triggers. There are 3 types of buildings which I have placed on the map and made regions for. I want to set it up so that every 30 seconds of gameplay the player who owns the building gets money. I want to either make it so you have to attack the building dont to so much HP or just place a unit near it to capture it. I also want to set up a timer. Can someone walk me through making these triggers? If so I would appreciate it greatly because I have been tring to set this up all day and have gotten nowhere.

-Thanks corpgus

Thanks the screens helped alot Im in the process of putting all these triggers in but I need help with a couple more, next im adding in sortve a skillike ability which has a long cooldown, I want it to drop like a big missle straight out of the sky and doo massive AOE and I have another where I want to fire a massive Laser beam from the sky. I already have the model for the laser beam but I need a model for the missle and I need to know how to put it all togeather.

Also I noticed how in some maps they have the starting units start at random spots on the map, how do I go about setting up the start up to do this?

If you could let me know I'd greatly appreciated.
-Thanks Corpgus