Bardsters post is excellent! however, if you just want to dabble, you could get by with:
craft knife
fork- for stitch marking and edge grooving
diamond awl
saddlers needles
some beeswax
18/3 linen thread
80 or 60 grit emery for shaping/tidying up edges
And buy Al Stohlmans "The art of hand sewing leather" a bit dated in parts but everything you need to know to get going and beyond, is in there.
cheers
Steve