Some of the details will depend upon the size of your organization, but the policy in general should include at least:
a) Capitalization threshold (i.e.--when you buy equipment, what is the lowest amount you'll depreciate versus expense, this will depend a lot on the size of your organization and what's material)
b) outline of depreciation time frames (suggest that this follow tax guidelines fairly closely as it simplifies things--because of some tax advantages, current versus deferred tax will never match but the IRS times for depreciation are pretty fair)
c) include purchasing and accounts payable procedures and controls as part of the policy, either directly or by reference to other policies
Hope this helps. Also, if I gave information that was too simple, that you already knew, I apologize.
Would also suggest that if you're a SARBOX Rule 404 bank or a FIDICIA compliant bank you check your fixed asset and purchasing control goals for either of these and make sure you address them in the policy.