These are a great source of Nitrogen (green) to offset the Carbon (brown) in the leaves. I use about 20 pounds of grounds a week to keep my contained pile hot throughout the winter (mostly). During planting season, the grounds get added to compost/worm casting tea as they are a great bug inhibitor and quick source of N during the initial leaf out.
The key for me is to keep enough leaves through winter to mix with the overabundance of grass/hedge clippings/tree trimmings/garden waste (all greens) during spring, summer and again in early fall. With a little luck and dilligence, I have kept a 3-5 yard pile of compost above 150F in the center for over 6 weeks. After the 6 weeks, it cools for a month and goes on the garden for fall planting as a nice crumbly material. I used to sift the pile, but the larger pieces break down in less than a year in the main garden anyway. Saves me about 30% more time.
If only making leaf mold (leaf-only compost), make sure to stir the pile up on a regular basis. Leaves have a natural tendency to repel water after a few inches of depth. My first attempt at leaf mold left me with a big pile of dry leaves in the center compressed by the weight of snow and ice. I had to use a spade to cut it up and the center looked exactly the way it did when I pile dit 6 months before. Also, the type of leaf can affect the time and quality. Oak leaves are thicker than the "average" leaf and will take longer. Black Walnut has a chemical that will inhibit growth in other plants (juglen?). I use primarily maple and they work fine.