What you want to do with your desktop is certainly possible. When you set it up, you'll want to make 1 primary and two logical partitions; I've had windows get pissy at me for having multiple primary partitions before.

For the shared data partition, use FAT32 (vfat). NTFS is technically possible, but the native Linux driver has problems writing to NTFS and the workaround pointed to above doesn't support a lot of common activities, such as creating files.