Certified GKH Gardening Expert
Mulch can be as simple as the grass clippings from your lawn to wood chips to gravel. These articles should help:
https://www.gardeningknowhow.com/garden-how-to/mulch/choosing-garden-mulch.htm
https://www.gardeningknowhow.com/garden-how-to/mulch/mulching-with-leaves.htm
https://www.gardeningknowhow.com/garden-how-to/mulch/mulching-with-grass-clippings.htm
https://www.gardeningknowhow.com/garden-how-to/mulch/bark-mulch-in-gardens.htm
https://www.gardeningknowhow.com/garden-how-to/mulch/sustainable-mulch.htm
https://www.gardeningknowhow.com/garden-how-to/mulch/crushed-stone-mulch.htm
https://www.gardeningknowhow.com/garden-how-to/mulch/can-you-mulch-with-hay.htm
https://www.gardeningknowhow.com/garden-how-to/mulch/using-inorganic-mulch-in-gardens.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/how-to-improve-clay-soil.htm