I am a great believer in learning from others and ebooks are by way the easiest and cheapest way of learning assuming you can’t make it to Oxford and attend one of our courses
I found this useful post on photographyblogger.net I would add to their list anything by the excellent Craft & Vision people
Here is what PB say:
While there are countless eBooks out there on photography, it can be a daunting task to filter through them all. Which books are worth their price tag, and will you walk away with the knowledge you need to improve your photography?
We set out on a photography eBook expedition to bring you a collection of guides that deliver – ones that will enhance your craft and widen your knowledge, so you can focus on enjoying your photography. Whether you’re buying for yourself or for the photographer in your life, these 7 eBooks can take your photography to the next level. See the full post and list of ebooks here
This is one sample from the post
If you’re looking to enhance your photography – that is, take what you have to another level – Ten is a solid source of inspiration that will help you grow as a photographer. Author and humanitarian photographer David duChemin is well-known for his eBooks, which are sold through Craft & Vision. Although he has authored many, his eBook Ten has earned a reputation as being a staple for photographers who have learned how to use their camera and are searching for that next step.
The eBook outlines ten ways to improve your craft, and none of them involve purchasing more gear. At $5, it’s already well worth the price – but as an added bonus, each step is followed by a creative exercise to help get you into the mindset needed to further your craft.
Oxford School of Photography 