When you have worked your way through Hoke and feel confident enough to start experimenting, the first thing to do is perform the acquaintanceship experiment Hoke presents. If I recall correctly, they use pure gold and silver as starting materials - so there will be some initial outlay.
Standard solution are often useful and some of those experiments tell you how to make them, as well as finding out just how dilute the metals in solution can be and still be detected with test solutions.
edit: acquaintanceship experiments