I just stumbled across another website where someone had created a tutorial for creating a Roll20 character sheet. I can’t yet vouch for it, but it looks very thorough and worth a look.
Here are the chapters in that tutorial.
- Overview and Plan
- HTML Overview
- CSS Overview
- Getting Started With Roll20
- Putting It All Together
- Using Flex
- The Body
- Advanced CSS
- Javascript Overview
- Reacting in Roll20 with JavaScript
- Roll Templates
- Advanced Topics
- Publishing Your Sheet
I also have a lot of articles on making character sheets, but a second view is a good thing.