How do I sum up numbers connected to repeating names?

I guess I will start with the fact I am in a Business Statistics course. I wish it was a normal class but distance learning is pretty much all the college offers anymore in the subject.

Anyway I have an excel assignment that has about 4000 orders for wood. I am suposed to find the company that ordered the most wood and of what kind. I am really at a loss for how to do this and have combed over my book quite afew times trying to figure it out. However it has little if any excel info and nor does the CD that came with it outside of how to install data analysis tools. I figure I need to find a way to get excel to combine the numbers together for orders from the same company but after trying for afew hours I have gotten no where. Any idea how to do this?