Just a suggestion...
If your document has a chapters like a book, break down the document save each chapter seperately. Then import each document into Indesign as part of a book. InDesign can then update the page numbers and chapter numbers for you.
There's no a priori reason why it should be a problem. If you have a lot of cross-references or footnotes it might be.
Whether you want to work with Book files is a pretty open question. My limited experience is they are more hassle than they are worth. Also, in CS5.5, there is a fairly serious bug that causes page numbers to be messed up on book export, which a number of people have been seeing recently. For that reason alone, I would stay away from book files.
The general advice for importing text into InDesign applies. Try to make sure you use paragraph styles well. And think very carefully about your plans if you think someone else might continue to edit the Word file after you start layout in InDesign.
This is a major project and will require a fair amount of "advanced" technique (like using Styles properly), whether you make one file or a series of combined chapter files in a Book (In ID, a Book refers to a container file that holds information about other documents and is used to coordinate them and ooutput to a single finsehed document. It has nothign to do with waht the content actually is). The advantages I can think of to using a book over a single file are ease of navigation (fewer pages to scroll through in any document), some convenience if more than one person is working on the project as multiple docs can be editied by differnt people simultaneously, and a (very) small bit of additional safety from loss. With a single file, if it's damaged the whole thing is damaged, with a book, you lose only one document and the rest are still good. For a project this size, especailly if it has any cross-references (which are very flakey across documents) I think the advantages are minimal compared to some of the potential porblems John has raised.
But the main reason I'm posting is that I get the sense you are a new user, and I STRONGLY suggest you take some time to get a little training before you dive into something this big and dig a hole that you'll have trouble climbing out of. Lynda.com has some great video training, and a lot of new users find Sandee Cohen's Visual QuickStart Guide to be an excellent book (it's the most recommended book on this forum).