You may wish to consider:
Company website, investor relations and annual reports
Most essential components of the annual 10-K filing include:
But if you use a subscribed resouce such as Capital IQ it has the advantage of pulling together company produced data in one place. Go to the News, Events and Filings section to find Company annual reports and 10ks or look for the link to the 10k at the top of the company profile.
Glassdoor - website where current and former employees anonymously review companies
Personal networks: fellow students or Alumni (Alumni Hub.) You can search for LBS alumn in CIQ.
Google the company. Try using the search string: [organization name AND company culture], then sift through the results.