The Right to Remain Toolkit is a guide to the UK immigration and asylum system. It gives an overview of the legal system and procedures, with detailed information on rights and options at key stages, and actions you can take in support of your claim, or to help someone else.
You can find it (with summary translations in several languages) here
For a quick guide to the UK Asylum process Jubilee + have produced this useful website
https://jubilee-plus.org/refugee-network/about-uk-refugees-and-asylum-seekers/the-asylum-system/
