You can start by posting int he right forum. Then you can follow the instructions some good fellow will detail for you there.
Alright, alright, 'tis your first post, so i'll let ya off, but in future, please remember that just because you have a mac mini, doesn't mean that any questions you have go in this forum.
You have a few options for transfering the files:
Networking: You can use ethernet, wireless, or firewire to connect the two computers together. You can then simply drag your files onto your mac mini from your notebook.
CD/DVD: If your pc notebook has some sort of disc writer (CD or DVD) then you can burn your data onto a disc, and transfer the files that way
USB: If you have a USB memory stick, you could use that (though if you have a lot of files and a low capacity stick, that could take a while)
HDD: If you have an external HD, drag the files onto that, then hook it up to the mini and drag them back off
If you are going to continue to use your PC notebook, then look at
www.foldershare.com - it auto syncs designated folders on your pc/mac so long as they both have an internet connection - i use it to sync some folders on my iMac/iBook and it works very well
Hope all this helps