There aren't that many how-to documents on the Microsoft Customersource website. However, this one has to be one of the most important must-reads for all Navision (Dynamics NAV) end users and implementers wishing to setup fixed assets in Navision.
The article is titled - "How to Set Up Modified Accelerated Cost Recovery System (MACRS) Depreciation in Fixed Assets" and can be found here:https://mbs.microsoft.com/customersource/documentation/howtodocuments/msd_navsetupmacrsforfa.htm
For end users, you will need to be current on the Microsoft Enhancement Plan in order to view the document.
This document will teach you how to setup Navision so it can properly depreciate fixed assets according to IRS specifications.
As an implementer, I always encourage the client to use Dynamics NAV for all of their accounting and bookkeeping. This is especially true since the system can be easily setup and used. In addition, keeping all the books in Dynamics NAV will allow you to freely choose the right CPAs for your company without having to be held prisoner by one CPA. It also ensures continuity of your records should you have to switch to a new CPA.