Michael:
The best place for reproduction manuals is Binder Books. The next best place is probably your Case/IH Dealer. I am not a great fan of the repros from Case as they are not as clear as Binders, but in some ways are far superior to those from places such as JenSales etc... who charge an arm and a leg for their repros. Not sure what the deal is there, but Binder is the only licensed Reproduction House for IH Manuals and they offer the very best manuals.
If you are looking to buy original manuals, well

is a good source for a wide variety. Simply search for IH Farmall Manuals and you will be surprised at the number you will find. Be wary though, there are a number of people out there who are photocopying (so read the fine print) manuals and selling them on eBay, burning them to CD after inputing into a pdf file etc. These are not licensed repros, so save yourself some money.
Here is another option..
The Manual Server has different Letter and Number Series manuals available on it. Have a browse. Currently there are only a few, but as the collection grows and time is available, these scans will be available and uploaded to the server. IF anyone has noticed, there is a NEW set of manuals on the server. I ordered a complete set of B-275 Manuals for a friend, and part of the project was to scan em and put them on a computer for her hubby to use in the shop. So, while I was doing that, I uploaded a copy to the server as well.
There are currently A-B, Super A-AV, B-275 and H-HV manuals on the server. I have a number more but are not ready yet. I still have a bunch of Cub stuff to do...,