You can safely transfer data between NTFS partitions Linux file systems.
Furthermore, using Samba to share from your Linux computers to your network, Windows computers will see the files on Linux file systems quite nicely. I've done it many times on my own home network.
The best guide I've found for setting up Samba is this one (PDF)
. It's the resource that enabled me to set up my own home network for the first time. I had what I needed before I was 20 pages in.
Just as an aside, please note that Windows "Homegroup" sharing works only with Windows. If you wish to share a Windows directory with Linux computers, use what Windows misleadingly calls "simple sharing."