Ctrl + wheel to scroll has worked for about ten years or more in many apps including MS Office and several browsers (certainly IE and Firefox, I think). Certainly on XP, possibly older Windows versions too (although wheel mice were much more a speciality item back then).
Office 2007 and 2010 suite has a zoom bar in the bottom right corner that you can use to zoom if you have no wheel - slide the slider or click the +/- buttons.
IE and Firefox both use Ctrl+ and Ctrl- to zoom in (larger) and out, and Ctrl-0 (zero) to reset. In fact, they also use Ctrl= (which is the key where + is written too, but strictly this would be Ctrl-Shift-= to get Ctrl+).
Opera does not recognise Ctrl= nor Ctrl-Shift-=, you can only use Ctrl-[numeric keypad]+. Ctrl- and Ctrl-0 are fine though.
Most recent trackpads have a scroll zone on the right and sometimes also the bottom of the pad, often marked with a series of short parallel lines. Sliding your finger in this zone will be interpreted as a scroll, if you configure this correclty (usually the default but if you have rebuilt a laptop from a plain vanilla Windows 7 install you may not have manufacturer-specific drivers or utilities unless you install them)