Welcome to the forum. I am fairly new myself and I will tell you, if you haven't noticed yet, the people here are friendly, extremely knowledgable, and love talking wood burning.
I have just recently asked the exact question that you have. I built my own wall protection panels and hearth pad for my VC Defiant Encore stove. This is what I learned about wall protection.
1. It must be completely produced from non-combustable materials.
Example. Tile mortered to cement board spaced 1" from combustable wall with ceramic standoffs with 1" opening around all sides and bottom..... OK
Tile mortered to layer of cement board backed with plywood spaced 1" from combustable wall etc..... NOT OK!! Plywood backing is combustable material even though it is protected by tile and layer of cement board. No combustable materials allowed.
Tile mortered to cement board spaced 1" from combustable wall with 1" wood blocks with 1" opening around all sides and bottom..... NOT OK
Cannot be spaced with wooden blocks. Wood a combustable material and not allowed!!
2. It must be spaced a minimum 1" from combustable wall.
3. It must have an unobstructed 1" opening around top, bottom and sides to allow ventlation around the back side of the panel. You are allowed to mount a mesh (like screening as long as it's not combustable) over the top and sides so that nothing can fall behind the wall protection.
4. The panel must be large enough so that with your stove set at the proper clearence from the combustable wall (check your clearence charts in your manual and on the decal on the back of your stove) with wall protection that when you measure diagonally from any rear surface of the stove, to the nearest combustable wall surface, you are further away than your stoves clearence spec for an unprotected wall. (I hope you understand what I mean here.)
Keep in mind your stove pipe clearences from wall and ceiling!!
I am sure I missed alot and others will add but his should be enough to get you started and planning.
Rich