I'm using VirtualBox with Windows 7 as the guest OS. However the max resolution setting I can get in the control panel is only 1264x602. How can I get up to the full HD resolution that I have in the Windows 7 host?
Try to install VirtualBox Guest Additions.
You may need to allocate more RAM to the virtual video card.
In Virtual Box and Vmware they provide Guest Tools with makes your guest OS to work in normal way and let you communicate with Host hardware.. for example use USB ports from host OS.
First of all check the documentation for your guest OS. that how much memory to split between Host and Guest Os.
After this follow this link to install tools / Guest Additions on Guest OS.
there are few questions which are similar to your. check this.