Out of IT Support for 3 years need help!!

I was an IT support. Tech, but left due to travelling but since I have been home I have found it increasingly difficult to get any sort of IT position due to technology always moving and now im at a stand stilll.. I can hardly remember anything so im constantly failing when asked technical questions at interview stage!!

Is there any1 one in here who can advise me on what materialI should be reading to get to grips with it all again? If so where to find the information on the net.. What exams I should sit?

Any help would be very good

Thanks
Kev