Some of these are in the sidebar, but I thought it would be nice to give a description of each. Also included in the list here but not in the sidebar are helpful links for general Scouting information (not LDS-specific).
AmericaJane.net - I just recently discovered this site. It is full of easy to follow explanations of all of the youth programs of the Church, including Boy Scout and Cub Scout basics. If you are brand new to the Cub Scout program (as a parent or leader) you might find her Cub Scout Cheat Sheet especially helpful. She also has a blog called America Jane Speaks, where she not only posts about Scouting and other youth programs, she posts about great FHE ideas and other relevant topics.
LDS Scouting Resources - This is a page put together by LDS Scouters in Virginia. It includes a PDF scan of the Scouting Handbook as well as some other helpful and inspiring resources.
LDS Scouting Relations - This is an informative site from the Francis Peak District of the Trapper Trails Council. It includes links to several Power Point presentations (some with PDF versions as well) including "Best Practices of Successful Scouting Programs" and presentations to give to parents of new Cub Scouts and Boy Scouts.
LDS_CSL Yahoo Group - If you don't mind creating a yahoo account (or you already have one) this group is definitely worth checking out. It is a great source of information, advice and encouragement for Cub Scout leaders in the Church. Members range from leaders brand new to their callings looking for advice to those that have been a part of Cub Scouts and the group for years, who are very helpful.
U.S. Scouting Service Project - This is a website you can spend a long time at without seeing everything. It is filled with general information, ideas, sparklers and sections like Ask Andy and Baloo's Bugle.
Boy Scout Trail - Another site with explanations and information about both the Boy Scout and Cub Scout Trails. This is a great site for information about Advancements as well as sparkler ideas. I like it when I need to look up requirements for belt loops or other special awards.
Kismif.org - "Awesome Cub Scouting" - This is another source for Baloo's Bugle. It also has a blog on the front page that offers tidbits that might be handy to Cub Scout leaders.
BSA Uniform Website - A new interactive website by the BSA with an easy interface for finding out exactly what goes where on uniforms for all ranks and ages.
The following are articles and files that I think are especially good and worth sharing with others in your Pack/Troop/Ward:
Message from the Young Men General Presidency (May 2010): Four reasons Scouting is used as the activity arm of the Aaronic Priesthood
Cub Scouting is the Foundation (Church News article featuring Cheryl C. Lant)
The Importance of Woodbadge Training by Charles W. Dalhquist II
Q&A on Popcorn Sales and Other Church Fundraising Policies
Church Policy Concerning BSA Registration
Here are direct links to Scouting resources on LDS.org:
Information for Scout Leaders
Possible Activity Correlations for Cub Scouting and the Faith in God Award
Statements by Church Leaders in Support of Scouting
Requirements for Adult Religious Knot
If you have any links you'd like to add to the list, please leave a comment.