cfv - You really are an arse****.
@XvvBDNV - I think most people have the same concerns when changing positions. The process is arduous so it helps if you can get it right first time.
Glass door is one option. However, View with an open mind as there a lot of disgruntled ex-employees on there who is see it as a platform to just rant.
See if any of your network on LinkedIn work or have links to people at the organisation
See if the company you are applying for, features in any best company lists - e.g. Times list
The interview process is a 2 way thing - 1) do they they want you and 2) do you want them ?
During the interview you can ask some probing questions. e.g
How did the role come about ?
What would be expected of you in first 3-6 and 12 months ?
What are some of the biggest challenges the person in role would face ?
What training / career development would be available ?
If you got offered the role, you could then ask if it is possible to meet some of the team.
Hope this helps.