One of the most useful things when I started playing guitar was a chord chart that laid the chords out by how you might actually want them. Rather than a simple list of all the majors, then minors, etc it had them in groups of:
- Relative Minor
- Sub Dominant
As I didn’t spend enough time paying attention in GCSE Music that doesn’t really mean very much to me but you might recognise them better as C, Am, F and G7 or E C#m, A and B7.