There are various platforms you can consider to source out such programs. Either JVZoo or Clickbank is a good start. Some years back, CJ (Commission Junction) was extremely popular BUT this has since seem to wane over the past 2 years (my 1.99 cents).
Another consideration is which NICHE to be your primer for these affiliate programs. If you need help in selecting Niches, I can provide you FREE Access to this Webinar - you will get tremendous value out of this session to help you shortlist your options.
Happy Hunting and Giving!