First of all was the trip from Kharkov to Kiev. We took the express train from Kharkov to Kiev. It's 200% better than the regular train. Instead of a beat up left over soviet era smoke filled smelly rat trap disguised as a train, the express train is actually on par with trains from western Europe. Buy a second class ticket. The second class seats are like first class seats on an airplane. No need to splurge on a first class ticket.
We also rented an apartment for the day instead of getting a hotel. For about $75 we got a complete 2 bedroom apartment with a separate living room, complete kitchen complete will all appliances, plates, cookware, etc. in a decent neighborhood not far from the consulate. Stay away from the center of the city. The apartments there are old and run down and cost much much more. Hotels are the worst because they are extremely expensive in Kiev, even for Ukrainians. Most want double the cost of an apartment and give you only a single crappy room.
One of the gotchas about this consulate is the security concerns.
Go to http://kiev.usembassy.gov/visa_visitmemo_eng.html for details but basically the idea is that the only thing you're gonna bring inside the gates is your wallet (no purses), passports, and your documents in a clear plastic see through folder. There is no place outside the consulate to put your bags. Best bet - leave them at the apartment or take your bags first to the baggage check service at the main train station in Kiev. Since most people will be taking the train anyway, its a good place to leave your bags before you head off to the consulate. Keep in mind they are not lockers, just a check in service so don't leave anything valuable in the bags.
The first thing you need to know about the consulate is that they do not open the gates until 8am.
They do not open the gate any earlier for any reason whatsoever, even if you happen to be 8 months pregnant like my wife was, so don't even bother to show up earlier than necessary. On that note I need to say something about the appointments for the visa interviews. You are not the only ones with the same interview time. We discovered after getting there that we were only one of three people with the same time slot. Also, punctuality is not a Ukrainian trait it seems at the consulate. Our 8am appointment started at 8:45am when the window slid open. The first thing that everyone seems to do inside the little interview room is start forming a line. The first thing the Ukrainians working inside will be to tell everyone to sit down. Just keep your seat until you are called. They have a list they go by according to the appointment schedule and will call you up to the window when they are ready for you. At the window they open up the medical exam envelope and any envelopes they have of the original material you may have submitted during the process. They will want originals of everything. If they collected the originals from you either in the Ukraine or in the states, they will have it. They will also ask you for any originals of documents if you only sent them copies before. Basically they are collecting all the original documents together for the interviewer.
Gotcha number two.
Bring everything you can think of, even if you don't think you'll need it. Photos, airplane ticket stubs, copy of your spouse's passport pages showing entry and exit visa stamps from the nice folks at the Ukrainian border (not required but really handy), letters, copies of emails, whatever. The more the merrier. Place all the "extra" stuff in a separate clear envelope away from the documentation. The consul will very much appreciate this. Also bring any W-2s you may have if you haven't yet filed for a new tax return. The requirement is to show proof of income. If you've already done that then they will have you tax returns. The problem is that the Ukrainians at the consulate don’t understand out tax systems. Their paperwork says they need to get a 1040 from everyone. If they see a 1040A or a 1040EZ they automatically go into a spazz mode demanding to see the 1040. I actually had the Ukrainian lady tell me that perhaps the state I come from may allow a 1040A but that I needed to have a 1040 instead. I almost busted a gut on that one!
Now, we all know as Americans that we either file a 1040, 1040A, or a 1040EZ but they seem to think for some reason that a 1040A or a 1040EZ is "not good enough". If you encounter this little gotcha, just ask for an American. In fact, if you get told any kind of crap that seems really stupid, just ask for an American. I saw so much garbage there settled in seconds once an American embassy worker got a hold of it. Bottom line, if they try to tell you still need something or something is not good enough, just ask for an American and most of the time it will be resolved immediately. DO NOT LEAVE until you speak to an American!!!!!
Examples of this was when the Ukrainians demanded original documents when all you had is a certified copy, knowing correct tax forms, explaining to the Ukrainians that we are not forced to file taxes until April 15 and the immigration process is based on LAST year's taxes anyway, asked for paperwork you are not required to have, etc.
About money and tax returns. They can't make you show newer income information if they have what they need from the previous year but you are certainly able to add material, such as a new W-2, if such a document will help your case. The important thing to remember is that eventually everything will be seen and read through by the AMERICAN consul. From our experience he's a man with mountains of common sense is a real pleasure compared to the rest of the Ukrainian "gang" working there.
Side note: the Ukrainians at the consulate seem hell bent on making your visit as difficult as possible.
The Americans seem hell bent on making it as pleasant as possible. 
That goes for everyone from the gate guards to the consul himself. Just keep that in mind while you are there.THE GOOD PART. Once the interview is complete, the consul will hand you a pink tear off with a serial number on it. If you get this it means you are approved and you are on your way. What you need to do next is go to the FedEX mailing windows (INSIDE THE CONSULATE GROUNDS) next to the gate building where you entered. The window is in the same section as the outside covered waiting area. Complete a form for mailing your passport to your Ukrainian address, pay the fee in Ukrainian money (about $10) and get a receipt. MAKE SURE you write down the serial number on the pink form and the telephone number for the SMS tracking system you will see next to the FedEX window. SMS is the only way to track your passport on it's way to your address. They say it takes 10 days but we (and everyone else it seems) gets their passports in about a day or two. WARNING!!!!! Be at home the day the package is supposed to arrive and have your fiancé / wife's Ukrainian blue passport ready. They will need it for delivery! They DO NOT warn you ahead of time when they are coming. The only way to find out is to send an SMS as per the instructions you will see at the FedEX window area. It will tell you the time and date. 2nd WARNING!!!! They are usually early on the delivery so just have someone there with the blue Ukrainian passport all day to make sure you get your passports.
We had an 8am appointment and we left at about 11am. We took the afternoon express train back to Kharkov and were home the same night. Two days later, early in the morning, our passports and sealed envelopes arrived.