I have started using After Effects today and have two major problems:

. I am importing footage that is 2 mins long, but only 30 seconds of it is showing in the timeline. But, this isn't an issue where I need to extend the timeline to see the rest - it seems that only 30 seconds in physically present - as after it runs the end it loops. Where has the rest of my footage gone?

. I am importing movies as a .mov file, but when exporting lose a lot of quality. I have tried a few different settings. How should I export to retain the good quality?

Thanks.

Not sure about your first question.

I always export out of AE using Quicktime Animation codec at full quality. You shouldn't loose any quality that way. What is the original resolution of your files? Are they for example raw DV files?

Are you sure the issue is not the duration of your composition? Ctrl+K opens the Composition Settings dialog. Make sure the duration matches or exceeds the length of your footage.
An easy way to create new compositions is in the Project Panel to drag your footage and drop it on the "Create a new composition" icon. This way AE automatically matches the composition's length, resolution and framerate to your footage.