Adjusting the shocks is completely seperate from adjusting the coilovers. You adjust the Koni's with a little knob at the very top of the shock. So to adjust the front shocks, just pop the hood and turn the knob. For the rear, pop the trunk and adjust the rear. Some shocks like the KYB AGX have the adjustment on the shock body making it a real pain to adjust quickly/easily.
As for the coilovers, they simply adjust the height of your car. You have to jack the car up, some cases take the wheel off, and spin the spring perch to raise or lower the height on each corner.
The Koni's are rebound adjustable. A lot of people think that adjusting the shocks to their stiffest setting will magically make their car handle worlds better but this isn't true. You are not reducing body roll or anything like that. You are changing the rate at which the shock controls the movement in your suspension. Allowing for more or less control and grip during cornering and even while driving straight when you hit bumps. In some cases you're only making your car handle worse by reducing grip.
It depends on your spring rate, the road conditions, tires, other suspension modifications, driving style, blah blah. Best bet for a simple daily driver would be to play around with the settings, front and rear independently, until you find something that is comfortable for your typical driving and streets you frequent. Not too low and not too high of a setting that you feel the suspension has the most control when driving through rough roads.
Also remember with coilovers that if you make any height adjustments after you've had an alignment done, you'll need to re-align your car. It isn't as simple as playing with the height whenever you feel like it and drive. You'll eat your tires up and your car won't handle as best as it could.
