If a sponsor gives your team money or contributions, you should thank them on a page on your website. If they are large sponsor and donate thousands (or possibly tens of thousands) of dollars to your team annually, a great way to thank them would be to put links/logos on your homepage or on a page header/footer.
(However, you should technically ask all companies before putting their logo on your website, even if they sponsor you. Many corporate "branding" ideologies prevent you from putting their logo on a certain colored background, or cropping/resizing their logo certain ways, etc. as they want to have positive corporate branding.)