1. Create a table using one of the existing tables in SQL Scripts\BaseTables.  If your module will support custom fields, also make sure to create a table that ends in _CSTM.  If your module will support many-to-many relationships, then you will need to create a relationship module similar to ACCOUNTS_BUGS.
2. Create the _Update and _Delete procedures using the spSqlBuildProcedures stored procedure.
3. Create the views using one of the existing modules as a template.  You should create 3 views, one is the core view, followed by _List and _Edit.
4. Create the script to add the module in Data\MODULES defaults.1.sql.
5. Create the script to add the shortcuts in Data\SHORTCUTS defaults.1.sql.
6. Create the script to add the list view data.  The files are GRIDVIEWS defaults.1.sql and GRIDVIEWS_COLUMNS ListView defaults.1.sql
7. Create the script to add detail view data.  The files are DETAILVIEWS defaults.1.sql and DETAILVIEWS_FIELDS default.1.sql.
8. Create the script to add edit view data.  The fiels are EDITVIEWS defaults.1.sql and EDITVIEWS_FIELDS defaults.1.sql.
9. Create a new module folder in the web application.
10. Copy all the files in a similar module to the new folder. Then rename the namespace in each file to match your new module name.  Products is a good module to copy as I have just created this module and it has all the core features.  I also typically rename all words in the old module to match the new module name.
11. You will probably need to comment out the procedures to your new module until they are ready.  When the procedures are ready, you can navigate to _code\Procedures.aspx to generate the SqlProcs.cs file.  The goal is to automatically generate this file so that it is always perfect.

All is possible with the open-source version.  The SplendidCRM Professional provides you with the source code, which really amounts to lots of sample code on how to add data to the layout tables.