We will be visiting Bordeaux during the first week of September and are interested in visiting the famous wineries in the region. I've been to the various websites and some state that they only allow visits to 'professionals' (e.g. Cheval Blanc). Should I still attempt to make appointments? Ones we are interested in are:

Chateau Margaux
Latour
Chateau Lafite Rothschild
Vieux Chateau Certan
Le Pin
Chateau d' Yquem
Cheval Blanc
Ausone
Chateau Cos d'Estournel
Chateau Léoville Las Cases
Chateau Ducru-Beaucaillou
Chateau La Mission Haut-Brion

Has anyone been to the ones above?

What do I need to include in the letter to request a visit?

Also, how many visits are recommended in a day?

Thanks!!!

I have been to Chateau Lafite Rothschild at Pauliac. It was by appointment only, so yes, I would attempt to make an appointment. Not only that, I could only afford to buy the Mouton Cadet - which is not the most inspiring of choices and one that is readily available in any supermarket in the UK for £5.
Not that it will help you, but I far rather enjoyed the "village" vineyards of the Beaujoulais region. Perhaps lower your expectations and visit a more realistic "cave" in the Bordeaux region?

It's unlikely you'll be able to make an individual appointment at most of the well-known ones unless you have some believable wine credentials or accompanied by someone who does.
Better idea would be to present yourself at the Tourist Office or the Maison du Vin,, both on the cours du 5 juillet in the center of town, and sign up for a small-group tour. There are myriad possibilities, and some tours will take you to some of the well-known wineries that won't take individual appts.
Also, as AR points out, you can have almost as grand a time just touring on your own. Head for St-Emilion first and fan out from there. It's grapes as far as the eye can see, and no shortage of nice little welcoming wineries.

Many of these Ch. are 1st & 2nd growth. Unless you know someone who can get you in, they won't open the doors to you. The '00 vintage of those you mention retail between $150-500. You may have luck at Cos and Ducru, but why bother. If you want to purchase, you shouldn't have a problem at any fine retail shop of which there are several in the town of Bordeaux. If you want to tour, why not visit an up and comming Ch like Figeac or Monbousque or Pavie Macquin in St Emillon. Look to the 4th & 5th growths as they are more inclined to open their doors. If you are still adement about touring a first growth, have your local merchant try to arrange a tour.
Bonne chance,
Gregg

By e-mailing our requests we were able to get appointments to see 5 estates while we were in Bordeaux--Haut Brion (a private tour), St. Geroges, also a private tour by the owner, Chateau Lynch-Bages, a group tour, Chateau Pichon Longeville--a beautiful building newly remodeled, also a group tour and at Chateau Margaux, another group tour where we not only didn't feel we needed to buy wine but they wouldn't sell any. We are not professionals, just interested wine drinkers. Each was a very different experience. Most last about an hour and were very informal, primarily relying on the visitors to ask questions or identify what they wanted to see/ learn about.
If I recall correctly we did two one day and three another. I wouldn't advise trying to do more than that. It would get repetitious and be difficult to get from place to place without seeming rude by trying to leave a group early or some such. Access guides has a guide to French wine regions. We found it helpful for identifying which Chateaus do and do not permit tours, which require appointments, etc. We enjoyed our winery visits very much. I hope you do too.

Hi everyone. Thanks for the comments...

jmv: Can you please give me some tips on writing the e-mails? I've sent a couple already and most have come back as 'NO'. I've heard that you have to be butter them up a bit in order to get in...is that true?

My traveling companion wrote the e-mails, probably just did the normal "we hope to visit your fine winery" etc. Maybe it's the timing of your visit. Most wineries do not permit visits during their harvest. If this year's harvest is expected to be during the first week of September you may just be out of luck.

Hi jmv. Thanks for the quick reply. I guess that is a valid reason for all the NO's we are getting.