Is there a setting to auto-switch between GPRS/EDGE/UMTS/HSDPA on my device?
By design, the device automatically switches between GPRS/EDGE/UMTS/HSDPA based on the service available in specific locations.

How do I turn on/off Wi-Fi?
From the Home screen, press the Menu key > touch Settings > touch Wireless & networks > touch Wi-Fi to turn Wi-Fi on/off.

Note: To conserve battery power, disable Wi-Fi when not in use.

When I click on a media link in the browser will it play the file?
When clicking a media link in the browser, the installed media player will play the file. Some file types may not be supported by the media player. It may be necessary to search Market for a Media Player that is compatible with the file type you are trying to access.

How do I connect to the Internet using Wi-Fi?
To use Wi-Fi on your phone, you need access to a wireless access point or "hotspot." On the Home screen, tap Menu > Settings > Wireless Controls. Select the Wi-Fi check box to turn Wi-Fi on. The phone will scan for available wireless networks. Tap Wi-Fi settings. Tap a Wi-Fi network to connect.