Dear Harapuzo,
it is nice to hear from some one interested in medical photography. The best resources for careers advice are the Institute of Medical Illustrators in the UK (Google them), or the BioCommunications Association in the USA.
My “day job” is photographing patients for their medical records. The work is largely technical, but it helps the medics in curing people in the hospitals where I work.
My passion is in making images that illustrate ideas. I find any ideas in science fascinating, and like to illustrate subjects that would normally be hidden the eye or the camera.
Most of my stuff done in Zbrush is sent to the Science Photo Library in London, to sell. I have had images published in “The Lancet,” “Focus” magazine (a popular science mag)," The Times" newspaper, “The Fortean Times.”
I haven’t earned a fortune, but I have loved making the pictures.
My advice is: contact the Science Photo Library and ask them for a list of subject that they are interested in. Then research the subjects in New Scentist, Scentific American, and on Wikipedia’s website. Then, have a go. Just send then some images.
The picture editors have scientific backgrounds, and can advise you if you need to change the images to make them accurate & saleable. Unlike some of the larger photo libraries, the picture editors at the SPL are helpful, and encourage new talent.
Hope that this helps,
Tim