2 Concerning File Associations?

I have a class IContact with various properties some of them being lists of other class objects. I have a public list of IContact. Can I write Contacts as List(Of IContact) to a file as opposed to a bunch of strings I then have to parse? I know visual studio has some data tools in the toolbox and a set of data classes, but I don't know how to use them or if they can help me write all this data to a single file.Second part of the question: I have associated .cms files with my program. But if a user opens the file, what code should the program run through in an attempt to deal with the file? This file is going to contain data that the program needs to read, how do I tell it to read a file when the program is opened vicariously because the file was opened?

I need to clarify these questions, I seem to have poor questions a lot of the time cause I don't get a lot of responses, and when I do get responses, they don't seem to answer my questions, I ask followup questions and then the thread will die after that usually..I seek not answers, but understanding, that I may not solve, but learn. What good is a fish without the skill to catch it?