My husband and I will be staying on the Brazilian side of Iguazu in Hotel das Cataratas for two nights. We arrive at around 3 the first afternoon, have the entire following day, and then leave around 3 in the afternoon the day after. I was thinking it might be nice to hire a guide for our full day to help us navigate the Argentinian side. Does anyone have any recommendations?

I dont think you need a guide as it is pretty straightforward by bus. Alternatively just hire a taxi for the day. Do be aware that, depending upon you nationality you may be required to pay a reciprocity fee of $100+ for entry to Argentina ( at least if you bother to go through immigration you will!)
I am sure the hotel will be able to source a guide for you although it will probably be the most expensive option.

Definitely worth going as you get a totally different perspective of the fall. The Brazilan side provides great panoramas whereas on the Argentine side you can get very close to the falls

I agree with Crellston, you do not need a guide to go there.

I find the Argentinian side better than the Brazilian one, but I like both. The ticket for Argentinian side, as far as I remember, is valid for two days.

I agree with the others, I can't think what use a guide would be. I enjoyed both sides, but I wuld rate the Argentinian slighter higher - I spent a long time standing right at the top of Devil's Throat, mesmerized.

Ditto. Just for one more vote to enjoy the Falls with no need at all for a Guide.

Thanks for the advice. I was thinking having a guide would ease the border crossing and mean I didn't have to as much planning I am feeling like this trip is coming up fast and I haven't spent enough time planning.

The border crossing is what it is, a guide has no influence with the immigration officials.

You can't get lost visiting the falls.