Preparing external HDD to be compatible with PC and Mac

[DoubleCheese]

My sister has a PC and a Mac. She wants to shift all her data off the PC and just use the Mac. Is there anything that needs doing to prepare an external HDD so that the PC data is accessible to the MAC?

 

[AbsenceJam]

Format as FAT32 or install NTFS-3G on the Mac and use NTFS.

 

[DoubleCheese]

Excellent, thanks!