Try following url, very comphrehensive, they will also send CD

http://tsc.wes.army.mil/products/standards/aec/toc-index.asp

These are fine for Architectural. What about Civil. They have little about existing and/or proposed roads, contours, topographic data, water, sewer... Who covers these things?

visit this website:
www.fema.gov

The California Department of Transportation (Caltrans) publishes its "Plans Preparation Manual" at the following URL:

http://www.dot.ca.gov/hq/esc/oe/project_plans/drafting/dpmanual.pdf

I need this info, too. What I've found so far is <www.dfcm.state.ut.us/standards/CAD%20standards%20page.htm>; and <www.metrokc.gov/ddes/lusd/cad.htm>;. Link to california's site(previous message) goes nowhere for me. Any tips?

p.s. The california site was great; just have to download it, rather than open at location...I'm still interested in more feedback on this thread

Check out this site http://www.cadonline.com/features/standards/standards.html

The problem is......
Almost every State, City, County and Community now has their own CAD standards and they usually are not the same. For instance here in Dallas we have the following authorities, all with different standard. You just have to obtain them from the entity you will work with.

Ballas Public Works
Dallas Water Utilities
Dallas County
Dallas Area Rapid Transit
Texas Dept. of Transportation
Most of the 20 or so suburbs also have their own standard.
Most work with Microstation, no Autocad.

Try looking up standards written by the American Institute of Architects(AIA).  They have recently completed drafting and cad layering guidelines for civil and architectural drawings done in Cad.  However, as previousl mentioned, every public agency has there own standards.  The ones I refered to above are slowly becoming required by some federal agencies.  Good Luck.