The Library Skills for Study database has a module on referencing, understanding plagiarism and has activities to test your skills. It is not exactly the same as the LHS version of Ulster Harvard but will help you understand the general principles which are the foundation to good referencing.
Another useful resource is the Cardiff University Information Literacy Resource bank which includes some useful tutorials on citing and referencing.
Don't worry about the exact form of Harvard used - it's not quite the same as that used by LHS but the basic principles are the same.
The following quizzes will help you check your understanding of referencing and are fun.
When to Cite - Cardiff University