How often to suit at a con?

Well...how often do you want to?

Greetings, Wolfgirleh!

In reading your question, I'm a bit confused - I'm not sure if you are asking how long you should wear a fursuit, or how often you should wear it.

The first is a question of endurance.  There is no rule about when you can wear your fursuit, except that it isn't a good idea to do so while waiting to register for the convention (and we recommend that you pre-register, to minimise that wait), as the people manning the registration desk must be able to see your face to match it with your photo-ID.  Aside from that, it is permissible to wear it at any time, for as long as you can stand to.  But remember - wearing a fursuit, even only a partial, is physically demanding and draining, and can leave you soaking with perspiration and risking heat exaustion and dehydration, if you aren't sufficiently innured to it.  While in the suit, you also experience a dramatic degree of sensory deprivation: Vision, Hearing, Smell, tactile sense, all are highly restricted by the suit.  So is your ability to just breathe, due to the head, and after a while, that can make even the simplest of exertions wear you out, and make your movements awkward and clumsy, though an experienced fursuiter (or their handler) will recognize the onset of this, and know enough to retire for a while and get out of the suit.

The second question is a matter of convenience.  I don't believe that anyone wears a fursuit, partial or otherwise, for more than a portion of the day, partly due to the discomfort and endurance issue, but also the fact that you will want to do other things at the convention other than just wear your suit.  Eating, sitting in on a panel or other programming, and the necessity of using the lavatory at some point, these are issues where you will likely prefer to NOT be wearing a fursuit.  This means getting unsuited occasionally, and perhaps taking the opportunity to dry out and air out the suit.  While there is a "Headless Lounge" for taking off your head and taking a break from suiting, it isn't a changing station, you would have to do that up in your hotel room.  If you are staying at the Westin, that means at the least making your way into the hotel, and waiting to catch an elevator up to your room (NOTE:  Fursuiters get priority access to the elevator, but it still means waiting for one to come down to the lobby), and if you are at one of the other three hotels, then you will have to walk outside into sultry Pittsburgh summer weather, and walk a couple blocks on city streets (remember!  Restricted Vision and Hearing!) to your hotel, preferably with a friend to look out for hazards and make sure that you do not collapse along the way, and THEN get to your room to change...

...All of which seems mighty inconvenient, but that is just lazy ol' me.

I think your best bet would be to spend the first day there watching the other fursuiters, and asking questions, like you did here.  Of course, fursuiters can answer the questions here, but only YOU can really judge what the obstacles are, and know what your limits may be, and plan accordingly - and for that, you need to actually scout the place out first, in-person.  And to avoid being stuck in the fursuit during some event which you wish to see or participate in comes up, you will need a copy of the program schedule - usually posted here in the week before the convention.

I hope that what I've written here doesn't discourage you; and I'm sure (and I hope) that some of the fursuiting regulars will answer your questions more directly.  But in the end, to safely and accurately gauge when and for how long you wear your fursuit, you will need to know some things which can only be known from personal experience, and perhaps those who follow this reply will relate their own experiences here, rather than just say "morning, one hour; evening, one hour-plus, both times ending an hour before planned meal breaks to allow for recovery and a cool shower" or something like that.

Good Luck!

Whenever you feel like it.

You stop when you're done!

It all comes down to how much you can handle.  As vulpes said endurance is the biggest factor in length of suiting time.  I know of people who have gone entire conventions wearing their suit with the exception of short cooldown periods and food. (myself being one of those people >.>)  The important thing is to know your limitations and what other things you wish to do during the sonvention time so that you can properly plan for when you wish to suit.