EASAs explanatory notes to the Basic Instrument Rating (BIR) (11/2020).
EASAs newly updated (11/2020) examination procedures for the CB-IR and BIR theretical knowledge exams.
Learning objectives for the EASA CB-IR and BIR can be found here. (11/2020).
EASAs newly updated (11/2020) acceptable means of compliance and guidance material for Part-FCL (licensing) when it comes to BIR (Issue 1, amendment 10), e.g. flight test tolerances and description of the BIR modules.
FAA – Federal Aviation Administration
The FAA has a wealth of excellent books which are completely free. However, there are great differences on how we do things between the FAA and EASA, so be careful and double-check!
Patrick Lienhart’s guide to EASA CB-IR
Patrick is an instrument instructor based in Graz, Austria. He’s got an excellent guide to the mysteries of CB-IR.
The best way to practice for your exams will be by using aviationexam.com.