Creating a new module: basic steps?

[Guido1982]

I took a look at this link for creating a new module and have some questions. First off let me explain what my module should do:

• It'll create a connection to Exact Online accounting software via their API. For this I only need a settings template where a user can set the client ID, client secret, division, return url and maybe some options.
• I'm going to create some workflow tasks that will read the credentials from the database and use them to connect with Exact Online. On every invoice save, for example this will be used to establish the connection and send the invoice.
• Later on I'd like to create a cron that reads from exact if invioces are paid (it has a bank link so in Exact this is automated) and set invoices in coreBOS to paid as well.
  

Now for the questions:

• I understand the vtlib module creation will auto-create tables and include the module name here. The only table I need is one where I can store the values in the settings page. Can I use the auto-created one for this? Or better to create table manually?
• I'm guessing the TPL files for the settings page go in the same folder as normal TPL file templates, but how do I create a link in the settings page?
• What exactly are the modules' 'event handlers'? This seems like a workflow task?
  

EDIT: Add attachment PDF with original vTiger tutorial for creating module