install Win 8 but keep Win 7,possible?

I wanna try Windows 8 but keep my Windows 7 installation,I mean I wanna have dual boot system.I have 2 partitons both are primary one is C where is Win 7 installed and the other is F where my most used documents are kept.The F partition is primary too.I can't delete all those documents,but I could maybe shrink that partition and make some space for Win 8.does that partition need to be primary to be able to install Win 8?
I mean cam someone write me some steps to have dual boot system?I read somwhere I just need to run throuch custom installation and install Win 8 on separate partitions.after installation steps it will automatically install dual boot.

Thank you.so windows 7/8 is only possible to install on primary partition?I think I already have 3 primary partitons,and can't create more.One partiton is used by ubuntu installation which was preinstalled when I bought my notebook.

Let us see a screenshot of Disk Management - Post a Screen Capture Image.

Tell us where you'd like to put Win7, by deleting or shrinking which partiition or partitions. You can put it anywhere you want.

An OS can be installed on a Logical partition as long as the existing OS which will host its boot files is on a Primary.