@Luke please do share your stuff! Creating a blog and putting it on there is a good place to start. Alternatively getting involved in an online forum where you can help other people who are asking questions is a good way to start ‘giving back’. I used to do a lot of that in Dreamweaver forums when I first started on the web – I didn’t know much but there were always people newer than me, and I felt I could answer all the easy questions 🙂