I spent my time working at home in my father's workshop, using parts I found around the house to build my inventions and to solve a few problems. I also spent time working at school in the workshops and labs or out on the lake. A mentor is a guide, not a solution. Don't be afraid to seek help from several sources and to use the resources that are at your disposal. Your presentation board should be appealing to the eye and should explain both what you did and what you found.
Pictures are very helpful and often say more than words.
Diagrams are also very useful as they allow the public to follow your train of thought easily and without confusion. Use color to separate ideas and arrows to direct your audience. Avoid buying expensive presentation tools. Your artistic touch is much more appreciated and shows your involvement in the project. Make sure your posters clearly outline what your project is about.