I believe you need to click the "additions" icon in the lower-lefthand bar, you can then select "install additions". i remember having a bit of trouble finding these myself... i would double check, but VPC refuses to see any drive states i created in 5.0 (even after i convert them).
I beleave that you can make a shared folder that VPC can see. Just make a folder on OS X and then point to it with VPC. You can do that with out the Additions. The additions give you stuff like drag and drop... which would be just as good