12/04/2011 With so much information constantly following it is difficult to make choices in selection of additions to this website. Collection development has gotten so complicated with not only monographs and databases to choose from but also other forms of media that are relevant to the subject. This is of course an ongoing process, not only to keep up with ever changing needs but also the everchanging tehnologies.
From the Go Librarians writing about libraries and the info society we get this article on CD. 
Evolving Hurdles: Collection Development
11/16/2011
I was talking with a friend the other day about how the problems of one library often are not the problems of another. Case in point: funding. In our world of haves and have nots, all libraries were not blessed with the same financial resources or political champions. In fact, just today, Chicago’s City Council voted unanimously to pass the mayor’s proposed budget, including severe reductions in funding and staff at a library that, until recently, has been revered as something of a sacred calf. Time will tell the outcome, but as history always repeats itself, one may suspect that Chicago will ultimately follow New York and Florida en route to full funding restoration. But I digress.
Libraries all being libraries, there are among them even more commonalities than differences. Libraries have classically claimed a variety of challenges to collection development and development planning, depending on the institution’s size and type. Outsourced development firms can homogenize a collection. Where development staff are unfamiliar with the demographics of a local usership, a library may incur a wealth of items doomed to be sight unseen, while omitting from its collection materials that are truly valuable to its patrons. Academic research libraries, while attempting to address the information explosion and provide access to increasing research publications, face escalating material costs and associated headaches. Add now fluctuations in the publisher-library relationship, inherent contractual issues regarding downloads, and debate over whether student interest justifies huge expenditures tied to digital collections. It’s at once interesting, concerning, and necessary to look at the varied barriers to collection development and to evaluate how these obstacles have evolved.
My questions are several. What are the greatest impediments to collection development today? How have challenges to collection development planning changed and how have they remained the same? Consortia and regional library systems have long shared materials to reduce costs and increase access. In what other ways are we overcoming barriers to growth and diversification? http://golibrarians.wordpress.com/2011/11/16/evolving-hurdles-collection-development/
From the Wellcome Library in the UK, 
there are many sources available, here in the US we can only visit virtually but there are resources available in many areas including the history of medicine and other health science resources. 
What follows is a description of their collections.
Collections
Archives and Manuscripts
Asian Collection
Comprises some 12 000 manuscripts and 4000 printed books in 43 different languages. The collection includes over 1000 manuscripts written on palm leaves, and others transcribed on silk, ivory, metal, bone, bamboo and tree bark. A medical prescription from ancient Egypt, written on papyrus (c.1100 BCE), is the earliest document in the Wellcome Library.
Medical Collection
An international collection of medical and scientific literature reflecting the course of medical thought and practice in different social and cultural settings. Comprises thousands of medical monographs, anatomical atlases, pharmacopoeias, 20 000 items of medical ephemera, a growing number of electronic resources and much more.
A collection of books, journals and other print materials, and electronic resources, dealing with the history of all aspects of medical science and practice, as well as allied scientific disciplines, social sciences and humanities. Currently comprises over 80 000 volumes in many languages, published from 1850 to the present day.
Medicine and Society Collection 
An extensive collection of printed and electronic resources providing information on a diverse range of subjects, including popular science, consumer health, biomedical science policy, research ethics, science education and public engagement with science.
Over 100 000 prints, drawings, paintings, photographs and other media, ranging in date from the 14th century to the present.
Moving Image and Sound Collection
Over 1300 films, 3500 videos and 1500 sound recordings aimed at professional and non-professional audiences, spanning 100 years of medicine and healthcare.