The FTP Site
Very early on an FTP site was set up in order to provide somewhere people could upload and download Sam Related files. These days many people choose to release their software via the web, but I'd encourage people to keep up the spirit of a central repository and upload to the ftp site as well.
To upload files simply used your favourite ftp software to PUT any files in the /pub/sam-coupe/incoming/ directory. You should normally include an associated text file detailing what it is you've uploaded.
In the case of files for the actual Sam, there are several common formats you'll come across:
LOAD "file.PAK" code XXXXX: CALL XXXXXwhere XXXXX is probably 32000 or 32768. It will decompress the files and then prompt you for a disk to write them to.
As well as games and utilites for the Sam, there are also various images and documents in the archive.