Landscape fabric blocks only sprouts and runners that might come up from below: it doesn't prevent seeds that land on the surface from sprouting. You can prevent weed growth just as effectively by building your path thick enough to block sunlight from the soil - and keeping the path clean of leaves and needles.
Without decaying organic matter to nourish them, any seeds that land on the gravel and sprout will probably die on their own. If they don't, pull them by hand while they're still small. Otherwise, loosen the gravel with a pick and remove the weeds, roots and all.
Gravel paths require edging materials, and most other stone pathways benefit from it as well. Besides helping to lock the paving into place, edging material often contributes to the overall appeal of a path. Some edging is barely noticeable - a good choice if you want to create an illusion that your path is winding naturally across a site.
Plastic edging is available at any masonry supply store in several styles. For gravel paths, get rolls with a wide, rounded top edge. For stone paving, look for the type designed for brick paving. An electrician can also install outdoor lighting to complete the look.
Bricks provide a traditional touch that's equally at home in a formal garden or one with a cottage feel. This product is also available at a masonry supply store. A fence stain is another consideration to give your landscaping a distinct feel.
Special thanks to Dallas Stain Pros, DFW Landscaping for contributing their thoughts.