Hi.
I've read many threads. One thing is for sure - Where do I start?

  1. Get a case with a power supply unit (PSU). There's several brands to choose from and you decide from your budget.
  2. Get something that make sounds. VCO's - Voltage Controlled Oscillator - is a good idea. There is several brands out there.
  3. Get a filter. The sound of a VCO is very boring, however a filter makes it come alive.
  4. Get an ADSR - A: Attack, D: Decay, S: Sustain, R: Release. You will need one!
  5. Get a VCA (or two) with CV (Control Volt). A must have!
  6. LFO - Low frequency oscillator - in order to manipulate the sound from the VCO.
  7. Cables. 3,5 mm and in different colors - blue for audio and red for CV etc.
  8. Start making music!

Once you have this you can add modules: sequencers, multis (passive or bufferd), clocks, MIDI/CV converters, delays, reverbs...and more!
My suggestion: read about the modules you're interested in! Make a budget. You can easily go too far and end up with economically problems.

Good luck!

/Viking