This may not have been mentioned in the article because it's too obvious, but I consider a database relational diagram to be one of the most important pieces of documentation for any database.  I usually create one with only the "core" tables but detailed column information and another with all tables including "look-up"s but with less column detail.

I also use the following sql to list tables, columns, and the "Description" text that EM's "Design Table" lets you enter.  I save the results to Excel and add the spreadsheet to my database documentation.

Note: This works on SQL 2000.  I have not tried it on SQL 7.0 or 2005 (yet) but it probably needs adjusting because it uses system tables.

--List tables, columns and column descriptions

select SO.name as 'table', SC.name as field,

ST.name as datatype, SC.length as 'size',

sp.value as 'description'

from syscolumns SC inner join

sysobjects SO on SC.id = SO.id inner join

systypes ST on ST.xusertype = SC.xusertype left join

sysproperties sp on  sp.id = so.id and sp.smallid = SC.colid

where SO.xtype = 'U' and SO.status > 0

order by SO.name, SC.name