Maintaining a gravel path doesn't take much effort. It's important to start a gravel path the right way to keep maintenance to a minimum. If everything is set properly, raking your gravel once in a while will be all you have to worry about.
The first thing you want to do, particularly if you are just starting to install a gravel path, is to make sure to start it out right. Be sure to dig out two trenches on either side of your path and dig out the grass and weeds of the actual path.
Treat the path with an earth-friendly weed killer to get rid of any current weeds. This is also part of your future maintenance so being thorough is important.
Another important part of long term maintenance for your gravel path is to use edge bricks or stones, or weather-treated 2x4s. No matter what you decide to use, placing it in the trench with a mallet to embed will keep it in place longer. This will also prevent the grass and weeds from creeping onto your path.
For the actual path, you should have outdoor plastic directly on the dirt. Then, put in a thick layer of sand before you add your gravel. This will ensure that you will not have to spend a whole lot of time weeding after installation.