Current fatty with a goal to becoming a healthy Triathlete!

Lofty goals are good ones!

If it helps, I started of at 6' 3", just under 400. I've since lost 130 (and shooting for another 60-ish more) and (had it not been for a mid race injury, finished the race) tackled a 70.3 this year (along with 2 sprints and an olympic) and I'm doing a full next year. Believe me you can do it!

How is your swimming capability?

How is your biking capability?

Sounds like you are OK with running? 

I'm no expert ... but the advice I got from my coach at the beginning is go slow at first. Your body will thank you later and it avoids injury possibilities.

Good luck with your goals.

This is just my $0.02 worth (and probably overpriced at that!) ...

I'd pick a sprint training plan that is balanced and use that to get started. Find a nice local sprint to set your sights on and train for that.

Open Water Swimming is a different beast and depending on what you will be swimming in, it can be wild. However, don't be afraid of it - it's totally manageable. If you're not used to doing OWS - find a local group or a location with support / safety and practice in the open water before your triathlon. Especially if you'll be using a wetsuit - it's much different swimming in a wetsuit too (better IMO, but different).

Congrats on the 5 lbs loss!

Sprint distances are usually (and they vary, in my experience) a 750m swim, about a 12-14 mile bike, and then usually a 5K for the run. I think the "official" distances by the ITU are 750m swim, 20km bike, and 5k run. However, there is usually some play in there for the course that your local sprint tri is run on. It's a nice bite sized distance to go get a feel for it. 

Wetsuits seem to run from, in my experience, from about $189 and up (some on line sales can bring it that low). Now is a reasonably good time to be looking because shops are often closing out last years models.

For anything that is a HIM or less, you just wear whatever you're going to race in. I wear tri-shorts and a tri-top under my wetsuit and then sometimes for the run, I'll throw a shirt on over my tri top depending on weather conditions and such.

My guess is that based on your location, you probably won't be doing any open water swimming until the weather turns, so there isn't a rush to buy a wetsuit.

I'm not sure of a good site for your area (as I'm in Washington), but I did a quick google search and found this 2013 calendar of races in Ontario. 

http://www.trimapper.com/tris_na/triathlonsbyst.php?country=Canada&state=ON

You might also ask your local triathlon shop what they know about local races.

I also bet that there are probably folks here that can point you better than I can.

You could always rent a wetsuit for your first race.  I think xterra rents them for about $50 (US).  If you decide to keep the wetsuit they take some of the rental fee off the cost if I remember correctly how that works.  The downside is you will not be able to train in it much before your first race since you get it maybe 5 days before and you have get the size is correct.  The plus side is since you are hoping to lose weight you'll get it closer to race day and you'll know your race weight.  Also if you decide tri's are not your thing because you don't like swimming or OWS your not stuck trying to sell a wetsuit.  I don't know anyone who rented this year so some of this could've changed.  End run, one less thing to worry about.

You just leave it in your transition spot. I have a towel on the ground with all of my transition gear. and I just throw it on the back of the towel behind my run gear as I do T1.

Iron-distance is different, but 70.3 and below that's pretty much how it goes.