You can use this pseudocode booklet to hep you get your head around this concept.
Check out the Bourne to code page! They have PPQ and coding challenges on this topic!
Extension material
Have a go at this self marking pseudocode tool.
What is an algorithm?
Flowcharts
Flow charts
Flowcharts explained
Pseudocode explained
Trace table presentation
Tracing algorithms worksheet
Trace tables exam questions
Trace table exam- Mark scheme
Tracing algorithms