Glen Allen Mcinnes
SOC-12
if you can find them for a fair price I would have to say TTB, the career books (LBB's 4-7)and either TTA (preferabaly) or a LBB adventure to kick off the campain. then I would start looking at suplements (starting with Citizens and the data libary books) futher adventures and ailen books. if you can't find any secound hand go for the reprints clasic books 0-8 is a must then its hard to pick betwean suplements, adventures or the aliens books as they all have stuff you will be able to use strate up and other stuff you will have to let lie for a wile, the JTAS books and and finily clasic games should be left for awile unless you and your group get right in to it. also you may find the first 80 odd pages of GURPS Traveller and the MegaTraveller Imperial Encyclopedia usefull.