Hi,the sections themselfes look fine, need to be reorded though. I would expect the Exhibition-section one of the last items in the list.I think people come to the playground with some arduino-problem already on their mind, so the absolute beginner sections should more be to the end of the main page.
I think a _getting started_ section should rather be on top. Maybe even highlited in some way. I know several people that are interested in this "arduino thing" but always end up like "maybe in my next life" because they simply had a look at an article like "code for the 74xx141", which currently is the first article in the _connecting hardware_ section. please have a look at it and imagine you're a second year fashion design student.
wowthat is hierarchical and non-hierarchical at the same time!D