You'll find some information about this here:

• http://mathematica.stackexchange.com/questions/29324/creating-mathematica-packages

Hi Ariel,<br />
<br />
We could Skype sometime if you wish and I can tell you what I know from my experience.&nbsp;<br />
Wolfram standards, by the way, is a somewhat nebulous target. &nbsp;IF one looks at the standard add-on packages there is are a variety of styles though there are common elements.&nbsp;<br />
In my experience I have found the model of using multiple ,m files for a project to be more trouble than it&#39;s worth. &nbsp;A project may in fact partition into distinct topic areas naturally and so suggest using separate .m files for those subcategories along with a master .m file for the high level Context. But often when one gets into the bowels of the project one finds that there are complex interdependencies that make that model break. In the &quot;old days&quot; of small memory and slower CPUs the use of multiple .m files may have made sense to keep from loading things that are not going to be used in a particular instance. &nbsp;But that is moot these days. &nbsp;I have written 60000 line packages that load just fine. &nbsp;And I then organize the code into (in a Notebook rather than Workbench which is very limited compared to Writing code in notebooks) separate sections and so on.&nbsp;<br />
Best,<br />
David

I appreciate your replies and both are useful (no problem with Spanish ;), however I'm more in the lines of getting advanced documentation online where the process of creating packages with multiple m files that "talk to each other" and how to call other packages needed in the new packages.  I have done this the hard way and I already have a solution but it would be good to know that this tedious process is documented somewhere.

The best place to lear how do deal with pack that I know is the book from Roman Maeder, "Programming in Mathematica".
Here is the link from Amazon.