So my question here is, what are the basics I’ll need to know before building my templates and adding them here?
It may be a newbie question and that’s fine, but the internet doesn’t really give me the straight up answers to my questions. Who better to ask than the authors of templates themselves?
The most important key is the design, if you are good with it you will not have problems.
Every template must be W3C validate and have a documentation.
If you are interested you can use http://www.framework-y.com/ for create your templates. In this way you will be able to convert them also in WordPress version without write any line of code, is require only to create the CSS design. If you are not interested to WordPress version (but you should due the earnings are extremely higher) and your designs are good I can be interested to convert myself your templates and split the wp earnings, but I require the use of framework-y.com or the work for me would be too long.