The gameboard may be where your artistic talents can be most useful. Since much of the action may be on this board, this could be the most important part of your game design. Use poster board, cardboard or even thin plywood for your gameboard designs. There are unlimited resources for game inventors, either through hobby shops and toy stores or crafted by your hand using the nearest hardware store or piece goods shop. The letters and numbers you may need can be hand drawn, stenciled or applied using rub-on transfers.
Graph paper is great for laying out the board's art work.
The game board need not lay flat, it can be 3-dimensional, with mountains, levels, stairs, etc. Remember, anything is possible because you are the inventor. Let your imagination be your guide. There are a number of tools and stuff that you will want to have around as you work on your games. You'll also need a place to work.