here's on perspective: 

they will likely want to be walked through your school / professional work to see what you talk about. 

do you talk about design, construction technology, detailing etc. 

do you have a particular focus or areas and topics that interest you.

they will want to know what software you're proficient in

and they will want to get a feel for you, personality, ability to work in teams, commitment, future plans. 

they would want to know why you think you're a good fit for their firm, what attracts you to the office

Don't forget to dress nicely.

Good luck!

Be sincere.. Talk about your portfolio, design work, inspiration/ideas for projects and approach when they ask about it.  Let them know you're keen on learning even though you have no real job experience.  Software skills will probably be a question or two and expected from most employees.  You can't be coming out of grad school today and not know the basic ones most firms use like autocad, photoshop, illustrator, some modeling program etc.

ask as many questions as they do. turn the interview into a conversation.

Wear a bowtie.

Thanks everyone for the comments. The interview went well, all my pre-nerves went away as soon as it started. They asked me when I could start and how much I was thinking... I take that as a good sign. 

I was a little confused about the pay. They aren't offering salary, but they said everyone was contract based, so more like hourly? For a first job I am really just looking for anything, especially with the market the way it is. Is the contract based pay something thats common in the field?

Glad to hear that the interview went well.

"Contract" means that you're not an employee, but a sort-of hired hand with fewer ties.  This generally means no benefits, no paid holidays, etcetera.  It also means you're easier to let go if work dries up.  Also, typically, the firm does not do any tax withholding from the paycheck, shifting that responsibility to the contractor.

As a contract employee, you will want to ask for 50% more than the equivalent salaried hourly rate. You're going to have to pay your own taxes and benefits (probably including self-employment tax, which is going to almost double your effective tax rate). That stuff's really expensive. And the paperwork's a bitch.

You won't have PTO, but they'll still treat you as an employee in the sense that usually contractors set their own hours and work as they like. But arch office contractors are expected to clock regular hours and be around all the time. Part of the point of being a contractor is that you control your own time and can come and go as you please. As an intern contractor, I seriously doubt they will give you that liberty, nor is it to your advantage at this stage in your career to have it.

Also be aware that even though arch firms like to hire full-time employees on a contract basis because they think it's cheaper, the legal status of a full-time professional contract employee can be very murky. For unemployment insurance purposes, for instance, any contractor obtaining more than 50% of their income from a contract job is considered an employee, and is subject to all the same coverage and taxes as on-the-books staff. This can often become a problem when they terminate the contract. I've seen this happen several times: contractors having to file formal complaints and go through an appeal process to overturn denial of unemployment benefits on termination.

Frankly, if it was me, I'd turn it down unless they hire you on the books. Being a contractor sucks unless you're a highly paid consultant. It's not worth the pain and aggravation.

unless i'm mistaken, 'contractor' also means you set your own hours, typically own your own equipment (software/computer) but there may be exceptions to that, work under your own direction (so you can't get idp hours), and you retain ownership of the copyright on all work you produce.

i don't think being hired as a contractor is all that common in our industry.  i think it's a scam, as a way for the boss to not have to pay for taxes or benefits.

i hope this is a good situation for you and i hope all goes well.

Frankly, if it was me, I'd turn it down unless they hire you on the books. Being a contractor sucks unless you're a highly paid consultant. It's not worth the pain and aggravation.

This.

Contractor, or consultant, usually means "high end" and billings that go with that.

Architecture has also made this term "viable" for interns.  How innovative.

The only way it might make sense for you to take an offer as a "contractor" intern is simply to be employed while you actively continue to look for a real job. It's always easier to get hired when you've already got a job, and you'll be learning something as you go. I wouldn't consider doing it for more than a couple of months though.

Save all receipts for any activities related to design/architecture to write them off against your contract income (trips anywhere, meals where you discussed design, etc).

I had a few contract gigs.  They didn't pay all that well vs salary, but by stringing together graduate short-term insurance (was available from the insurance carrier that provided my student insurance for $500/6 months), and writing off a lot of expenses (not necessarily directly related to the contract work, but related to the field) it wasn't all that much worse than a full salary.

Contract work dosent count toward IDP so how is it still considered an internship? 

Don't assume or stress over the whats/ifs/buts too much right now.  Its your first job.  Have an open mind and go try it for a week, few months or longer.  Worse comes, if you don't like it, just say 'Adios!' :) 

Thanks again everyone for the feedback. I just got a callback to comeback in because they want to offer me a position. I will be sure to ask a lot of questions on how the pay structure works. Some of my friends that work in the area said they have similar pay structures at their firms. So we will see what happens. If anything, this is my first job so I am just trying to get some experience under my belt. If I have to deal with some growing pains, I guess that's the price to pay for experience...

replace contract with temp or temp to hire and you'll have a better idea of what is going on here.

I'm in a similar situation in Germany, working 40+ hours for one company but am only a 'freelancer'. It's not the best situation to be honest. But in this economy it's easier for companies and small studio's to take on contractors or freelancers because they don't have to pay insurance and tax etc. (which the previous posts have mentioned). But it's not just the US that seems to be operating like this, I've seen it in the UK and throughout Europe.