Rosalind: Website for learning bioinformatics and programming through problem solving

I've used Rosalind in the past to learn about bioinformatics. I solved about 17 of the problems, which is about 6% of the problems on the site.

I think it gave a decent mix of guided learning and letting you figure things out on your own. I would say having some background knowledge in biology and coding would be necessary. It doesn't do a lot of hand holding, but there is some.