Widgets are not as easily usable as I would like ...
I'm sorry but statement is so vague I cannot address it. This is the main support page for widgets and on that page you will find links to descriptions and instructions for installing all available widgets. > http://en.support.wordpress.com/topic/widgets-sidebars
When it comes to locating the best theme for your needs we have Dashboard Theme Search Utility Feature Filters. Appearance > Themes
You can use the search utility and Feature Filters in your Dashboard > Appearance > Browse Themes > Feature Filters to locate themes of interest to you. (A-Z, Popular, Features)
Each theme has a thumbshot and a features summary description. You can browse and when you find one of interest you can click “Preview”. When you are ready to make your selection you can click “Activate”.
Currently, the following themes have the custom menu feature enabled: Twenty Ten, Structure, Vostok, Bueno, Enterprise, Notepad, Paperpunch, MistyLook, Under the Influence, Vigilance, Greyzed, Wu Wei, Blix, Cutline, Freshy, Contempt, Ambiru, Digg3, Koi and Modularity Lite.
Creating a custom menu allows us to change order of the list of pages, to mix pages, categories, and random links in your horizontal navigation instead of your theme deciding for you. > http://en.support.wordpress.com/menus/
If my answers do not address your needs then please post again and be very specific and detailed about what you want and need so we can provide the answers that score! :)
These are extremely important entries for new wordpress.COM users to read so they fully comprehend the limitations of working on this wpMU (wordpress multiuser) blogging platform. > http://support.wordpress.com/com-vs-org/ and http://en.support.wordpress.com/code/
Best wishes with your blog.