In reply to gavinpeach:
Your profile shows you have done a fair bit of rockclimbing but there is little mention of snow / ice winter routes or alpine climbing skills / experience. So a possible schedule could include:
-A few days doing some winter walks / scrambles climbs in the UK.
-Some longer mountain fitness days, perhaps linking climbs and scrambles together in the UK.
-Practising moving together roped up on ground you find easy.
-Crevasse rescue techniques practice.
Once in the Chamonix area a possible schedule could include:
-Check at the OHM ( Guide's Office for weather forecast and mountain / route conditions
-Perhaps go into the Aiguilles Rouges. Up to Index area for some mountain cragging with awesome views of your Mont Blanc route. Bivvy near telepherique for another day of rock routes or perhaps a more alpine route such as the Traverse of the Crochues which has lots of moving together scrambling and easy climbing at around 2,800 metres
-A visit to the Albert Premier hut ( hut or good bivvy spots ) in the morning can be combined with dry and wet glacier skills practice within a few minutes of the hut. Following morning you could put the skills together by choosing a route in the area such as the Aiguille Tour (3,500 metres) or combine the Tete Blanche and Petite Fourche
-Going up the Aiguille de Midi and either bivvy or use the Cosmiques hut. Lots of routes to choose from around here. As you say the normal route up to the Tacul is good acclimatisation or, if you have the skills, try a more challenging route such as the Contamine Grisolle. There are also shorter routes you can mix and match to help with acclimatisation such as the traverse of the Pointe Lachenal, the small ridge that leads up to the Cosmiques Hut or the Cosmiques Arete itself.
-You then need to choose which way up Mont Blanc you wish to go, depending on conditions and group ability. Of the easier routes my preference is to go up from the Cosmiques. You can return the same way but a traverse coming down the Gouter route makes a great day.
Personally I prefer to bivvy, if there isn't too much of a walk in, as I find some huts noisy and hot and I sleep better on a bivvy. Take earplugs if going in huts! However using huts means you can travel light, getting kitted up in the morning is a bit easier and more comfortable and some huts are a delight to be in. The Gouter hut does not fall into this category!
Just to reemphasise, check the forecast and mountain / route conditions regularly. Have fun!