Etsy. I like Hazylace the best.
http://www.etsy.com/shop/HazyLace?ref=seller_info
Yes, they still make them and you have to buy garter socks.
I have seen them come up from time to time on eBay.
Wedding favors can range anything from sugared almonds or candy to more expensive things such as shot glasses. A good place to buy one would be www.weddingfavors.org because they make personalized wedding favors.
Good question! I didn't know you could buy a dog as a wedding present!
No, you should not buy the first wedding dress you try on because there may be others that suit your body frame much better. Take a week of looking at wedding dresses off and on because trying to find a wedding dress in one day can cause you to blur your senses looking at one white wedding dress after the other. If you see a particular wedding dress you are interested in ask the shopkeeper if they can keep it on hold for a couple of days.
Amazon.com has a selection of wedding albums online. The wesbites www.topflightalbums.com, www.albumsinc.com, and www.somersetalbums.com are also good resources for wedding albums.
Since you left no information as to what city you are in it would be best to go to a wedding shop (phone around to get good prices) and rent the wedding guest attire instead of buying it. If you need to buy it at the request of another person then boutiques are a good place to go to buy either a nice skirt and top or a dress.
Buy a bridal magazine. Quite often they have wedding planners inside them. Also there are some good resources for wedding planning online.
Tiffanys.com and Cartier.com are both well respected jewelry stores online that sell a variety of wedding and engagement rings. If you are looking to piece together a ring from scratch check out bluenile.com for a wide selection of bands and loose diamonds.
If they are religious a figurine of their religion is nice.
There are many sites that offer wedding stationery, but if you prefer the person to person approach, try looking into paper stores or dress stores. There are many bridal stores to choose from!
Tuxedos can be very expensive to buy. It comes down to the question: Do you frequently attend formal affairs where they are required or preferred? If so, buy one, and make it a good one that will take a lot of wear. If you are going to a wedding and have no need for a tux in the forseeable future after the wedding, then rent.