How can I use my external hard drive for my Mac and PC

Is there an easy way to do this? And if I decided not to can I just take my most valued files from my PC put them in a folder on my Mac and then delte them later? Time Machine will save the deleted files in old backups right? Even thought they won't be in more recent backups?

I am new to this I have had my MBP for a year now and finally got smart and bought an external hard drive. I have already done an initial back up with Time Machine but this external hard drive has a lot of space, 1 TB so I thought that if I could also save files from my PC on it that would be great. My hard drive on my PC crashed not long ago and I ended up losing some stuff that wasn't backed up. I would mostly want to save photos and music and stuff like that from my PC onto the external hard drive as well as do my regular Time Machine back ups but of course it has now been formatted for my MBP. I hope I posted in the right spot. I wasn't too sure.

The easiest way is to format it to FAT32 using disk utility.
Both Macs and Windows can read/write, but the downfall is restrictions on file size.
I would partition it to 1x HFS+ which is Mac OS Extended (journaled) partition and 1x FAT32 partition (Windows).
Here are the different scenarios with Pros and Cons of different format types.
Post back with your questions once you have gone through it.
1 External Hard Drive for Your Mac and PC :: My First Mac - Help Buying and Getting Started with Your New Mac

Thanks for the info! I will read that! If I have questions I will post them! Thanks again!