I would definitely start by trying to build your knowledge with CSS Form Builder first. Since you have many forms to produce this will be a main tool that you will use in creating or modifying all of these forms. Being able to save forms as presets will save a bit of time and allow you to use a preset as a starting point for a new form rather than build it all from scratch.
You should start with the Getting Started Guide for Form Builder. Here is a link to the support page:
Once you have learned about using Form Builder I think the next part you should look into will be the conditional questions in the forms. This can be done using client side validation but it will require you to be familiar with the steps needed to apply client validations and there responses. The best place to get info on this is within the help for Form Builder and on the support page for Validation Toolkit:
Finally, if you would like to add Security to your site you could make use of Security Assist. The wizard will produce a set of pages for users to register, update and login. You can create access rules for allowing access to given pages within the site. Here is a link to the support page for Security Assist:
It can be difficult to provide an A-Z set of steps to achieve a particular goal since the goal will be different for most people and even when the goal is the same it may be desired to have the goal achieved in a particular way. Also, most of what you would like to create and add is not interdependent. For example, the only parts that must go in order are dictated by the nature of the desired result. You cannot apply conditional validation to a form that does not exist, the same goes for setting cookie values to form values, the form must exist first. For the other parts though, like creating your spry tabs or applying security to the pages do not have to be done in any particular order. I hope I have explained things well enough, please post back with any questions that you have.