If you capture a hyperspace gate it will lead you to it. Alternatively, you can just explore the resource pocket off in front and to the left of the starting location (past the inhibitors), that's where it leads.
Oh, and I will say, I am overall quite dissapointed with Homeworld 2. It has absolutely no replay value. HW1 still rocks in that department, even after playing through the second one. IMHO reducing the effectiveness of capture was what killed it, but saying that doesn't do much of anything. Of course, there really is nothing quite like jumping in to Hiigara with like 6 Heavy Cruisers, 18 destroyers (standard and missile), 20 multibeam frigates, and enough ICF's to not all be visable onscreen at once, plus 50 salvage corvettes. The imperials can't send enough ships to prevent them all being captured. And in the end, surrounding the flagship with your massive fleet (which has nearly doubled from all the capturing in the last level) and clicking to watch like 300 beams of death (many of them from imperial ships) slice the emporer up into bite-sized pieces. You just can't replicate that in HW2.