How do I point my device to a HTTP/TFTP Server? 

There are 2 ways to set up your HTTP/TFTP server. Use the device web configuration page. Login to the web configuration pages of your unit. Under Advanced Settings page you will find Firmware Server Path field. Enter the IP Address or server path here. Use the phone keypad. For BudgeTone Phones: From phone keypad, press menu button and down arrow to item number 6, press menu button one more time to get into the "Editing" mode. If the TFTP server IP displayed is not the one you want, enter the entire 12 digits of the IP address of your TFTP server. e.g., if your TFTP server is 192.168.1.100, enter 192168001100. For GXP2000/GXV3000: From phone keypad, press MENU button (round button), scroll down to Config-->Upgrade to enter the Firmware Server information. For ATAs: Unhook the receiver, press ***, press 13, enter IP Address of the Firmware Upgrade Server in 12 digit format ex. 168075215189. Use option 15 to select upgrade protocol (TFTP or HTTP). Can you explain the simplest way to update firmware in a local environment?

Download the latest firmware from website at Firmware Download
Unzip the firmware file and put all of them under the root directory of tftp server. If you don't have one, you can download the free
windows version TFTP server at http://www.solarwinds.com/downloads/
Change the tftp server's default setting from "Receive Only" to "Transmit Only".
Put the computer and grandstream products in the same LAN segment to do upgrading. For example: under the same home router. On configuration page of grandstream device, change tftp server 's IP address to be the IP of the computer it is running on, click "update" to save the change.
Turn on the TFTP server, and power cycle the unit.
Make sure the TFTP server is on the WAN side of the box (if you have a WAN interface like ATA486/496) and ignore the two cfg.txt configuration files reported missing.

If you don't have a DHCP server/router in your LAN and you are using static IP, you need to set up the gateway to be the broadcasting address of the LAN segment where you connect your devices to (for example, standalone hub or switch).

What precautions must I take before performing an upgrade?

Firmware upgrade is a simple yet crucial procedure. If done incorrectly, it could damage the unit. On our website we have list of instructions and warnings that should be read carefully before attempting an upgrade. You can find this information here (enter your product reference to get all necessary documents).

Where can I find the Firmware Version of my Grandstream device?

There are two ways that you can see your unit's firmware version depending on the product:

For ALL Grandstream devices
The software version is displayed on top of the Status web configuration page in a format similar to the following:

Software Version: Program--1.0.X.X Bootloader--1.0.X.X HTML--1.0.X.X The number series next to Program indicates the firmware version of the unit.

For BudgeTone Series Phones
Press "menu" button
Press up arrow button 3 times to get to item number 9 "codE rEL"
Press "menu" one more time to browse the "codE rEL"
Use up or down arrow button to see "B (bootloader)" and "P (program)" code date and version.
For GXP21xx/GXP14xx/GXP116x/GXP2000/GXV3000
Press MENU button
Scroll down to Status option and select it by pressing the MENU button again
Scroll down to Boot and Prog. Prog is the firmware version on the device.