http://forums.adobe.com/people/cdflash (Colin Flashman) is our resident Data Merge expert and has a lot of information on his blog. I think what you are suggesting is probably doable, but you may find it worthwhile to also invest in one of the cmmercial catalog plugins. It would probably be worth the time to set up a machine with a trial of ID CS6 and also trials of the catalog plugins to see what they can do.
InDesign's Data Merge works only with .txt or .csv files so an export from the access database has to ultimately be done. The feature will also only populate the placeholder fields placed into InDesign, and it can't interpret the data (e.g. tell that it is a dollar value, an address, needs to be title case, etc). At some point the file has to go from "template" to "merge" and it is normally once a catalogue is merged that proof-reading can begin and the errors revealed. From here, the question is then "do we do the alterations in the database or indesign", and how do we maintain versions? Data Merge is probably not the feature i'd use to accomplish this kind of catalogue work.
HOWEVER, InDesign does support the import of XML code, so if access can export an XML file then I'd pursue this option. I have only used XML to produce real-world products on a few occasions so I would suggest purchasing the book "A Designer's Guide to Adobe InDesign and XML" by James Maivald. There are tutorials in the book which I think the OP would find useful.
Otherwise there are plug-ins which can be purchased in addition to InDesign but I do not use them myself and could not recommend one over the other. Perhaps other posters who use such plug-ins may be of some assistance.
Data merge is great for one record-one/many page output such as direct mail campaigns, raffle tickets etc, but IMHO other solutions work better for producing catalogues.
Data Merge is also not a query return window (e.g. not a solution for producing utility invoices with many entries which differ from client to client).
I'll take a look into it. Thanks for your recommendations.
And thank you Peter for linking Mr Flash to this question. I'll report back!