I'm having some trouble understanding what you're trying to do.
You say you'd like details on the front page like client name, project num etc, and then have those details appear throughout the entire document. By that - do you mean the same details? ie - The same client name etc. Or do you mean you have a number of clients and you want their details to appear on each page of a document (I'm thinking sort of like a mail merge in MS word).
When you say 'across various master pages, without having to go in and type it for each master page'. This is a little confusing. Anything you put on a master page will appear on 'pages' in your document.
So putting the headings like Client name: Project number: on a master page would make sence, and you could then fill out the other details on each page.
A little more info on what you're trying to do would help.
As Flippy says, the details are a little vague, but it sounds to me like maybe you should read about Variables in the help files.
I think the OP is talking about text variables.
i'd imagine a better solution (if working in cs5.5) would be linked stories.
see this video @ adobe.tv:
Sorry it wasn't clear.
Basically we want to set up one template for client presentations that we open and use for all clients and projects.
I'd like to type the specific clients details on the front page, including job number etc and have those details appear throughout the rest of the document; in the header and footer for instance.
The rest of the document will be a different set of master pages to the front page
Hope that's clear?
No not a mail merge.
The thing is, I just want to have to type the client's name and project details in once - on the front page. And have those details appear throughout the rest of the document automatically in certain arrears - in the header and footer for instance.
This is precisely what Running Header type variables do. You have a choice of basing the variable on a paragraph style or a character style applied to the text you want to pick up. This is well-covered in Help.