I would like to secure a cabinet to a wall (ie it's fairly tall so has an optional support to prevent it from falling over). I understand in most modern houses walls are drywalls (ours was built in 1996 and is Canadian). Should I find a wall stud to attach the fixing to or can I screw straight into ? If so how do I locate the stud? Or am I able to screw straight into the dry wall? Thanks.

Never us just the drywall for support for a cabinets.

The old fashion way of finding a stud is use a finish nail and drive it in the drywall no more than 1" ( wires and things to consider)

Another way is the big box stores have stud locator's.

Scanners and Stud Finders (http://www.lowes.com/lowes/lkn?action=howTo&p=BuyGuide/StdFndrBG.html)

Be careful of wires that may be through the wall studs

Yep on both accounts. I have seen stud finders at Home Depot and the likes for $10. You can also shut off the lights and hold a flashlight flat on the wall. As you move the light beam across the wall you will probably see at least one drywall nail/screw spot. Measure in 16" increments from this spot and you should find a stud.

May not help here, but one way I locate studs, is remove a receptacle, feel inside the elcetrical box to see which side the screws or nails are on. If the box is 4", then measure 2" over from center of box, this is edge of stud,
3/4 inches over from there is center of stud, the rest should be 16" on center.
This works a majority of the time.
Kitchen may be on an outside wall, where you may have Fir strips instead.

Strat, you said 2', did you mean 16"?