Creating buttons for osCommerce is a chore. There is a “css button” contribution that I recall seeing years ago – but I thought it would be nicer to point out a really cool site that creates buttons for you – have a look at The osCommerce Button Generator.
Although the button sets are fairly limited – a nice touch is that you can play with the colours and text etc. Once you are happy with your button set, you can download them and then upload to your osCommerce site.
Creating osCommerce Buttons could not be easier!