Here is the info on mulch in general:
https://extension.umd.edu/resource/mulching-trees-and-shrubs
and specifically for veggies gardens:
https://extension.umd.edu/resource/caring-your-vegetable-garden-maryland

Personally, I use heavy duty landscape fabric (porous) on my walkways, held down with landscape fabric pins. It has been there for many years. This is not the "inexpensive" weed barrier type. Cardboard is another option, but this lasts for only 1 season and has to be held down with bricks, rocks or pins.

I do not use mulch on my vegetable beds since sanitation is important to me to minimize disease and insects. However, in the spring, I top off my beds with compost (Leaf Gro). This does not prevent erosion, drying out, or temperature control or weeds. 

If you want to use mulch, the least expensive is several layers of newspaper (not shiny or colored parts) but it has to be held in place. Another good option, which I have used is the past are "mini" pine bark nuggets (1-2"), which will stay in place and degrades over 1 or 2 years to improve the soil. 

Good luck,
Len