The famous "Weihenstephan" yeast from Germany. A widely used yeast strain that gives beer a clean finish and lets the malt really come through. Give this yeast a try and you might just have a new favorite!
This is marked as directly pitchable yeast and there are no rehydration instructions.
Some instructions for rehydrating yeasts: Suspend yeast in 4 oz of warm water. Do not stir. Let stand for 15 minutes. Stir gently. Add an equal amount of wort to your solution. Cover, let sit for five minutes, and pitch.