Reddit reviews John Kember - Piano Sight-Reading - Volume 1: A Fresh Approach (The Sight-Reading Series)

>Just for encouragement, is it safe to say that those 5 years actually gave me something?

Yes, of course. You're 5 years ahead of zero experience.

>Can I say that I started to play the piano at an early age?

I guess. Who do you need to prove yourself to?

>I’m worried that it was more like a waste of time.

Don't worry.

>What should I make my priority for now? Should I learn a bunch of theory? Should I play scales all day? Should I focus on ear training?

In terms of theory, you should understand the following:

• 4 chord types with all inversions: Major, Minor, Dominant 7, Diminished 7 (in all 12 keys)
  
• Major & Natural Minor scales (in all 12 keys)
  
• The Circle of Fifths & The Key Signatures
  
• Chord progressions like II-V-I or IV-V-I (in all 12 keys)
  
  That's just a start, but it should take you a few weeks of an hour practice daily to master the above. You don't need to "play scales all day". Once you've memorized them all, it should take 30 minutes of daily maintenance work to keep them in your fingers.
  
  >I currently pick pieces above my skill level and learn them slowly. I take around two-three days with three hours practice each to memorize them and be able to play without mistakes in every bar. After that I spend up to two months bringing it to desired speed and just polishing overall. Is that okay to do it? Perhaps it’s better to learn a lot of easy pieces instead?
  
  I think it's wise to look for quantity over quality in the beginning to intermediate stages of training. Spending a ton of time and energy on a single piece leads eventually to a certain dullness and falling out of love with the piece (and sometimes the piano!). If you're constantly exposing yourself to new pieces daily, that are more manageable in difficulty, you're exploring a lot of variety in musical ideas, learning to prioritize rhythm and spontaneity, and overcoming "perfection paralysis".
  
  Look at some of these interesting articles on the "40 piece challenge": http://sightreading.com.au/free-resources/40-piece-challenge.html
  
  >I’m thinking of buying one of those sight reading books. Do they really help a lot? Is that really important to focus on it now? At first I thought I’d wait until my sight reading improves naturally but I’m getting too annoyed with the slowness.
  
  Yes, Sight Reading is the most important thing to focus on. I like this series by John Kember: http://www.amazon.com/John-Kember-Piano-Sight-Reading-Approach/dp/184761132X
  
  >Any tips on ear training? Is that ok to start by transposing easy G1-G2 pieces?
  
  Transposing is more of a mental "theory" thing, IMO, than an ear training practice (although really ALL music study is ear-training). This site has lots of notation/theory/ear-training exercises (the app Tenuto is really good too): http://www.musictheory.net/exercises

Mikrokosmos (as mentioned) and the Kember series have been the best sources I've found.

Please check

• Hannah Smith: Progressive Sight-reading Exercises
  
  
• John Kember - Piano Sight Reading Volume 1, Volume 2 or Volume 3