Having the low down on a prospective employer is very important. it helps you look knowledgable at interview , and a look at the share price or company accounts/ website might put you off working for someone whose ethos or performance is not ‘for you ‘ !
Here are some great tips http://careers.guardian.co.uk/careers-blog/research-employers?CMP=
Lots of help with your new career or business too at http://www.karenperkinslifecoach.co.uk/career-coach-sheffield.html
Good luck !!!