My IT knowledge resides mainly in SW development. I have just some basic know how about networks.

On the net I tried to get information and read books in order to better understand the overall IT infrastrcuture, but all the sources I found are too generic or, mainly, too detailed in just one aspect, making me lost.

Could anyone suggest some books or web resources as good compromise in details? My goal would be able to understand the network issues and security threats when, for example, two remote system have to be setup and put in connection each other. Considering this scenario there are several aspects to consider: firewalls, intranet/internet interconnections, certificates for httpS, etc.

The argument is quite wide, therefore I was looking for something that might help to start to understand this subject without going too deep in details (Computer Networks from A.Tanenbaum is a wonderful milestone, but way too specific for my scope).

Thanks