Hello everyone,
this post might not be in the correct section but since it's related to .NET 4 and VS 2010 it's here.

I am developing a polling service application in C# using VS 2010. This application monitors a hot folder for xml files dropped in. It picks the file, reads them and creates another xml file. In between reading and creating a new xml, it also does some other tasks.

This application will run as a Windows service.

I would like to know the best practices in developing such a kind of application, specifically I am looking for answers to the following:

1. What is the best XML library to use (performance wise).
2. How can I reduce the application footprint (this is not mandatory, but I would like to work on it! Any idea is appreciated) in terms of speed and memory usage. The reason I think this is important because there will be other file read and write operations like writing to a log file (since this is a Windows service).

The idea is that once the app is developed, I would like to make it generic (wishful thinking! Maybe!) and put it on the internet and share the knowledge.

Any suggestions/ideas are welcome and appreciated.

Regards.