When I started to learn Mandarin I mainly focused on traditional characters which are used in Taiwan. I was looking for a resource which allows me to both see the characters used in traditional and simplified chinese. From a recommendaiton I got to the book Far East 3000 Chinese Character Dictonary.The book gives you the different meaning of a character, how it is used in different words and an easy guide in what order to write the strokes.
The prizes for the book vary a bit in different countries and especially in Europe it wasnt cheap. For me it was the biggest investment, but worth every penny. This book became a kind of bible in my journey to learn mandarin