I'm playing through the iPhone version of "Command And Conquer - Red Alert".

I've played older variants of C&C on other platforms so I know generally how RTS games work. But what I cannot seem to figure out is some specific controls for some units - in particular, I'm on a level that asks me to use an engineer to blow up a bridge, but I have no idea how to use an engineer to do anything but capture enemy buildings (and that I had to figure out for myself). Nor can I find the point of some buildings like a defense center.

Since the in-game guide is very basic and does not answer these questions, I was hoping there was an on-line manual somewhere that described what is going on in more detail - either from EA or someone else. Are there sites I can visit for a real manual?