Do I need to be careful when handling the cpu and mobo, as in are there any parts I can't touch?
I would avoid touching the contact points, such as the bottom of the cpu, the socket pins, I/O board connections (ie video cards). The oil on your hands can stick to it and tarnish them. Also, watch the components on your motherboard, you don't want to knock off a capacitor. When assembling your motherboard, its good to set on a semi soft surface because of the underside not being flat. I find it easiest to set the mobo onto of the box it came in. It's also always good to set it on something anti-static, like the bag it came in. Its just good practice, so just throw down the bag the mobo came in on top of the box it came in and keep that mobo on that until you are ready to install.
Other than that, just be firm with your connections, you want to make sure they are seated correctly. But don't be aggressive. Watch out for the cpu mounting mechanism, it isn't as nice as the LGA775 was. The lever will clamp hard, but it should bend ALOT. If it does, remove the clamp and place the bracket back over the CPU and try again. It takes a little force to clamp it down but not excessive force.