You can probably get the triathletes training bible on ebay quite cheap, or use Crossfit Endurance
for an alternative way of traning for one i.e less hours involved.
It's a fucking nightmare, got to be the most expensive hobby ever! Time wise as well as money invested. If you're not bothered about being competitive then you should probably note that it's the most competitive amateur sport I've ever experienced and the races are stressful as fuck. For a challenge I think you'd have more fun doing something like tougher mudder or spartan races where there's more people just having fun. There's no stupid rules about transition zones, the marshalls are less dick-ish and you don't spent the first 10 minutes of the race being kicked in the face/being groped by dentists in wetsuits.
Not including the bike, the wetsuit, the tri-specific everything, but just paying the money to travel to races and race-entry fees has got to be a tonne of cash.
the cyclist training bible is here
, triathlete's equivalent is very similar in layout and ethos, just a lot more focus on time management.