My absolute essentials are
- a guillotine (I've got a cheapie one from Crazy Clarks)
- a cutting mat (again, I bought mine from Crazies)
- double sided tape. I absolutely could not scrapbook without double sided tape. I don't bother with all the fancy glues and sticky dots
- lots of good quality cardstock.

Everything else is just icing on the cake really. I do a lot of my titles with a needle and thread - just sewing through the cardstock, so you don't even need fancy equipment for that.