As @ElectricalTestTech stated, you can get the Commissioning standards directly from NETA in hard copy or PDF form but it can be expensive. Sometimes you can find older copies selling on websites like eBay for a bit less.
When it comes to electrical drawings, try and get your hands on as many as you can. One-line and riser diagrams are good to start but also try and get some switchgear control drawings for a good challenge.
Try searching for “electrical drawing filetype:pdf” on Google, see what you might come up with. Many times you can find government websites that have project bid packages available for download that contain drawings.
One thing that will help you learn is re-draw the diagrams by hand and highlight the completed portions on the original as you go. This will really help you focus on each component. You might want to also review these references on TestGuy:
