Aswath Damodaran
In my opinion the best learning resource on valuation, by a long shot. Damodaran made available a long collection of teaching videos from corporate finance to valuing obscure companies but also free spreadsheets to help you value different types of companies. The fact that all of this content is made available to you free of any cost mades, in my opinion, from Aswath a great teacher but also a good role model, in a world that everyone tries to sell you something.
Check it out