Humm
This seems to be very intresting problem but very easy still good to be a final year project.
Regarding the technologies .NEt is the best for these kind of projects this supports the file upload and file download. Most importantly easy to learn and lot of help is available on these topics.

You will store all the files on a comman location or server to be accessible on client systems. so you will store them on server probably in some directories.

Storing a file directly in database is not recommend mostly because this take so much space on database. Mostly the files are stored on hard disk directly and their path is stored in database then this path is used to access files back. Hope this will help you. Please Let us know if there are any other questions