If you used VMware Fusion to install Windows, first make sure you have installed VMware Tools in Windows. Read > http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=display KC&externalId=1003417
Then, you will be able to change the Windows resolution as usual. In Windows, right-click in the desktop and select "Screen resolution". There are other ways to do this > http://windows.microsoft.com/en-us/windows-8/get-best-display-monitor.
There are not best recommended settings because it depends on the hardware of your computer: for example, if you have got 8 GB of RAM, you can assign 4 GB of RAM to the virtual machine (depending on the applications you use), or if you have got a Quad-Core processor with Hyper-Threading, you can assign more processor threads to the virtual machine so you can improve performance.