Perhaps you could tell me exactly what you don't understand?
You can't make Recovery Disks because Windows 7 lost its link to Recovery after reinstall which is common. Your Recovery partition is also useless if it won't run from boot using the steps in the Dell link I gave above.
If Recovery will run you can recover to factory condition which will allow you to make Recovery disks and keep the factory install if that's what you want.
Or you can leave it as it is. If the Recovery partition will not run when using the steps from Dell link then you can delete it and recover that disk space into Windows 7 partition if you want using steps we can give you.
The other small OEM partition is to run Dell Diagnostics using it's key given on the first boot screen. If it will run that way I would keep it but it will no longer run from Windows 7 after clean reinstall. If it won't run from boot there is a Dell Download to put it on a flash stick here: How to run Dell diagnostics from a USB stick
Most clean reinstall enthusiasts don't want any of the factory bloatware as there are much better versions built into Windows 7, like backup imaging which can re-image your HD or replacement from an externally stored image in 20 minutes. This is your own customized Windows 7 image, too. Backup Complete Computer - Create an Image Backup
I would only reimport the drivers
and programs which you absolutely need from Dell's website.
There is more information here on getting a perfect Clean Reinstall - Factory OEM Windows 7