I have an iPhone 4S and a PC running Windows 7 64-bit.
Setting iTunes and your iPhone to back up to iCloud is, in my opinion, a world of pain. It just doesn't work.
On your phone, tap Settings>iCloud> and then turn off Contacts and Calendars. Turn on Mail, Reminders, Safari, Notes, Passbook, Photo Stream, Documents and Data, Find My iPhone.Exit out of Settings.
On your PC, connect your iPhone via USB cable. iTunes may open automatically. If not, open iTunes manually.
Click on the iPhone "icon" on the top RHS of the screen. A new page will open with the options "Summary, Info, Apps, Tones, Music, Movies, TV Shows, Photos, On This iPhone". Click on "Summary" if that page isn't already open.
Select Automatically backup "TO THIS COMPUTER". Select options "Automatically sync when this iPhone is connected", "Sync with this phone over wi-fi". The other options are up to you.
Click on "Info". I run Microsoft Outlook 2010 on my PC. Therefore, on the "Info" page I checked "Sync Contacts with" Outlook, "Sync Calendars with" Outlook and "Sync Mail with" Outlook. I get a very nice 2-way sync happening between phone and PC when I sync with iTunes.