Home developing is one of those things that seems enormous from the outside and turns out to be, basically, careful cooking in the dark.
This is how I got started with HP5 — the classic black and white workhorse — without setting fire to anything important.
The kit you actually need
A developing tank (Paterson, secondhand, £15), a changing bag (£20), chemistry (Ilfosol 3 to start), a thermometer, and somewhere with running water that nobody else needs for half an hour.
That’s genuinely it. You don’t need a darkroom. You don’t need an enlarger. You don’t need to have thoughts about zone theory. Those are all optional luxuries for later.
The process, simplified
Load film in the changing bag. Pour in developer. Agitate. Pour out. Rinse. Fixer. Rinse. Hang up. Make tea.
The whole thing takes about 20 minutes of actual attention and results in wet strips of film with real images on them, which remains, every single time, a small miracle.
What you’ll get wrong first
Temperature. Nobody gets the temperature right first time. It matters more than you think.
Video version
The full walk-through, complete with me dropping the thermometer at minute 14, is on the channel.