Welcome to the Forums Marlo!
Tesseracts are simply geometric shapes, and their importance to travel is not a direct relationship. They are often reffered to as a "4-D Cube"; just as a square has two lines that come together at each corner, each at 90o to the other, and a cube has three lines in that same relationship, a tesseract has a fourth line at its corner which is at right-angle to the other three.
The important thing to travel would be that, since we can logically deduce the existance of such a shape (even though we can't see it or even "picture" it), it is rational to state that that "fuorth line" does exist, and the direction in which it points is one not visible, nor even "envisionable" to us 3-D critters. If we could find a way to point ourselves in that direction, we could take a trip without moving through the space (and therefore the time) with which we are familliar. This would certainly put a new "Wrinkle" on travel!
(BTW; Say 'hi' to Aunt Beast for me, wouldya?)