Just a quick recommendation of a useful resource. Few of us may get the opportunity to study at bible college or seminary, but every Christian can benefit from the sort of teaching provided there. One way we can achieve this is using the otherwise "dead time" while we drive to work, make dinner or clean the house. An excellent resource to help us do this is the Biblical Training website which has a range of talks available for download from lay to seminary level.
I'm working my way through the New Testament Survey which is taught by Dr Bill Mounce and I can highly recommend it.