How to evaluate normative requirements for a new device/design?
If you are designing for a European market start with the directives that are needed to CE mark your product. These are all freely available on several websites. Work down these to decide what directives are applicable then it should become clearer what EN documents are required to be adhered to for your product.

Here is a good starting point. It's the UK government's CE marking guide and contains a list of all the directives that may apply.

Here is also another useful website where you can download pdf copies of all the directives. This one is the low voltage directive - wade through until you get to section 1 (general conditions) and you can seek further guidance from this site. If you download the pdf of the guidance and go to "scope" it begins to list the requirements and specifications that may be involved.

There is guidance available for all directives. You should also download the "Blue Guide" - it has a lot of good information and links but is more than a ten minute read.

And finally this document entitled "the new approach guide" contains flow diagrams of how you should approach testing your product.