Data for analysis/research? Suggestions?

Hi guys,

So the deal is I'm a student analyst in a VC/PE fund next to my studies which I'm very grateful for.
This is the first time they've hired an actual "analyst" and am thus currently the only in-house analyst.

However, I need some help from you guys.

One of my main tasks is to usually conduct an analysis when requested by an investment manager. Usually no cases are alike, and each case is very unique.
My superiors are not quite certain about what they actually expect when requesting an analysis on a specific case.
Most of my cases are VC-cases, regarding startups/market analysis/competition/due dilligence etc. in the world of ICT (IT, web, tech.......).

Thus, I currently feel that most of my analysis tend to be a bit "vague" as I have a lot of difficulty finding relevant and thorough data in general?

I would love to get some help from you guys.
How would you conduct a general analysis on a typical VC/PE case?
And how would you go about to find data?

One example:
I recently got a case where I was asked to look into the car-rental industry in Europe; specifically clarifying the largest key players and the rental volume in each European country.
I basically ended up scrambling/crawling the web for different, random data, trying to put together something useful - but I honestly don't feel my results are particularly good!

How would you go about to find this kind of info???

Help please