Here are some links to more websites which themselves contain more links to other organisations.
Here are some useful links on the EWM website.
This is a British semi-governmental organisation devoted to advancing women’s academic careers in Science, Maths and Engineering.
WISE’s mission is to increase the gender balance in the UK’s STEM (Science, Technology, Engineering and Mathematics) workforce, pushing the presence of female employees from 13% as it stands now, to 30% by 2020.
More links on the AWM website.
Founded in 1971 as a committee of the American Mathematical Society (AMS), JCW is now a joint committee of eight mathematical and statistical societies, all mainly based in the USA.