What documents do I have to give a new tenant?

The How to Rent guide, the EPC, the gas safety record where there is gas, the EICR, and the deposit prescribed information.

All of it goes to the tenant at or before the start, and you need to be able to show you did. Email with a read receipt or a signed acknowledgement both work, guessing does not.

Give the current version of the How to Rent guide. Handing over an old edition counts as not having given it, and that has consequences for possession later.