• NexStar+ Hand Control - 19 Feb 12
• Hand Control Compatibility - 25 Feb 12
• Basic Information on the CGEM Series - 5 Jan 09
• How to Upgrade Hand Control Firmware - 14 Jan 06
• How to Upgrade Motor Control Firmware - 2 Feb 08
• Celestron's Online Spare Parts Store - 4 Sep 10
• Backlash and How to Set Anti-backlash Compensation - 7 Apr 03
• Power Sources for Your CGEM Scope - 9 Oct 05
• Questions about RS-232 Control and Upgrades via PC - 5 Jun 02
• Firmware Versions on the CGEM Series
• Common Problems with PC to Scope Communications - 13 Jun 03
• Common Problems with PDA to Scope Communications - 4 Jul 04

• Using NexRemote on the CGE, CGE Pro and CGEM with Hand Control Versions 4.13 and 4.15 - 18 Jan 09
• Ports and Connectors on CGEM Scopes - 5 Jan 09
• SkyScout Connect - Interfacing Your Scope with Celestron's SkyScout - 30 Nov 08
• NexStar Alignment Stars - 2 Dec 07
• Cancel a GoTo in Progress - 18 Jun 07
• StarGPS-NX - GPS Receiver for Celestron Scopes - 4 Mar 07
• Skyan - Basic Wireless Control of Your Telescope and Motorized Focuser - 7 Jul 06
• Use a Handheld GPS Receiver with Your Celestron Telescope - 7 Aug 05
• SCT Corrector Plate Removal - 15 Apr 05
• Ken Hutchinson's Article on Building a PC Port Adapter for the AS-GT and CGEM Mount - 10 Dec 04
• Some Settings Are Not Reset by Factory Settings Command - 24 Sep 04
• Cleaning Optics - Part 1 - Glass Surfaces - 22 Mar 04
• Cleaning Optics - Part 2 - Mirrors - 27 Mar 04
• Collimating Schmidt-Cassegrain Telescopes - 15 Jan 04
• Extending the Hand Control Cable - 23 Dec 03
• Get a Full 2" Aperture for Your 11" SCT - 11 Dec 03
• Pin Connections in Auto Guide Port - 24 Nov 03
• No Response Errors - Updated 4 Nov 03
• Manual Hand Control for the Auto Guide Port - 31 Jul 03
• Jim Towers' Excellent Battery Tutorial and Guide - 7 Jun 02
• Possible Fixes for Hand Control Misbehavior - 11 May 02
• Ease Collimation of the SCT Advanced Series Scopes with Bob's Knobs - 11 Jan 02
• Warming the Hand Control to Prevent Sluggish LCD - 17 Dec 01
• Accurate Centering of Alignment Stars - 22 Aug 01
• Replacing the Power Connector on Your Power Source - 20 Dec 00

Another source for CGEM information is the Yahoo CelestronCGEM Group.  The discussions on the Group provide great information:
http://groups.yahoo.com/group/CelestronCGEM/