First install Win7.
In Win7, create partitions for root, home etc in an extended partition.
Then using the livecd, you can install PCLinuxOS.
Bootloader may be installed in the root folder or as suggested by the installation into the HD0 or whatever that it suggests.
If it is done as per the installation by PCLinuxOS, the dual booting will be taken care of by Linux.
If you install bootloader in its root, use EasyBCD Ver 2 (and above) by Neosmart technologies for dual-booting, that is controlled by Windows.
Before installation, please read about dual booting.
If done on the same hard drive, there won't be much of a problem.
Only if the OSs are on different hard drives, you need to exercise some caution.
Best of luck !