Salaam Alikum (Peace to you)
I think it's wonderful that both you and your husband are exploring this together. If I can be of any help, please let me know.
"1. I would like to begin praying daily, but I don't know how, and I also do not speak Arabic. Are there any sites where I can learn the proper forms? Do the prayers need to be in Arabic?"
You don't need to know Arabic to pray your 5 daily salat (prayers) it's quite alright to use your native tounge until you learn some arabic.
Here is a free multimedia tool to help you learn your salat:
http://www.iisna.com/downloads/cybersalat.htm and a site that explains how to perform the ritual washing (wudoo) and the prayer:
http://www.jannah.com/learn/prayer.htmlOther sources:
http://www.islamicfinder.org/prayer/index.htmlRemember it's quite alright to say it in english and use "crib notes, or cheat sheets" until you have the basics down. And if the motions are too physicaly demanding, it is quite alright to do the prayer sitting in a chair. The important thing in Islam is the intention of our deeds, and remember this time is for you and your God to be together.
Try and memorize Sura Al Fatiha, the first sura in the Quran, at least in English then Arabic as you will say this once each rakat. It's not hard, it's only 7 short verses :).
Also I recomend the Athan (Azan) software found at
http://www.islamicfinder.org/ . That will give you the prayer times for your location as well as the direction of the Kabba.
"2. Both my husband and I would like to attend Mosque. Even though we have not converted, would we be welcome? How do I go about this? What are the customs to follow?"
Everyone is welcome in the house of Allah it matters not if you are not Muslim. If you live in a large metro area then finding a Masjid (mosque) should be pretty easy.
http://www.islamicfinder.org/ can help you find one near you as well as offer more general info.
You may wish to call ahead and see if there is a community night. This is a good time to visit. Fridays around 1 in the afternoon is also a good time as that is when the friday surmon (Jumma Kutbah) is given.
As far as customs, simply dress modestly and be respectful. Normally the Women and Men have seperate meeting areas, although this is not always the case. Shoes are not permitted inside the mosque and there is a place for them just inside the door.
And please keep in mind, many of the Brothers and Sisters may not be American or very conversant in English, so some may be a little shy, please don't take this as them being aloof or alienating.
"3. We both would like to learn Arabic so as to be able to read the Qur'An in its non-translated form. Any tips?"
There are a number of resources free and paid on the web, but the best way would to see if a local mosque is offering Quranic Arabic courses. Normaly these are free and there is no substitute for learning with a real person.
Don't feel intimidated by everything. We have the rest of our lives to work on perfecting our Islam :) Take it easy, just little steps are the best. I'm also an American convert, going on about 4 years now, and if I can learn then anyone can.
If you have anymore questions, please feel free to ask. :)
Peace.