Do you need to keep your Yahoo and GMail contacts/calendars separate? If not you could import your Yahoo contacts to GMail and sync the Yahoo calendar with the GMail one, that way everything shows up through your Google contacts/calendar.
if i do it like this is this a one time thing? I do not need to keep them seperate. so everytime i ad a contact do i have to resync Thanks
It looks like the calendar sync should be a one-time setup. Check out this Google support thread for a guide.
The only thing I found for contacts is a way to import your Yahoo contacts to Google, so if you add any contacts to Yahoo after doing this they will not show up in Google (you just have to import them again). Here's the other Google support thread for that.