First, the math part:
5% by volume means 5 mls of sulfuric acid per 100 mls of solution. To make 1000 mls of solution you would need 50 mls (5 mls/100 mls x 1000 mls = 50 mls).
For the procedure:
You would want to add the acid to the water to begin with for safety reasons. You would measure out 50 mls of sulfuric acid and SLOWLY add it to a large volume of water (something like 800 mls water). After addition, you would use a 1 liter volumetric flask to bring the FINAL volume of solution to 1 liter. So, the amount of solute would be 50.0 mls but the amount of solvent (water) cannot be determined. You just add sufficient water to make the final volume 1 liter.