Review of the Arduino Expermentation Kit – by Steve Hoefer….

Pluses
Frankly I liked almost everything about this kit.  Unlike most kits which just dip your toes in something this one really gives you what you need to dive in, go off on your own and start making stuff.

• Versatility.  Other kits come with a few LEDs a button and a photoresisor and the number of different  things you can do is limited.  This kit comes with tons of inputs and outputs, enough that you can easily remix them into your own gadgets easily without buying extra parts.  Among other experiments I built my Comfortableness Measuring Instrument. But I’m sure you can come up with something better.
• Breadth.  Although there are only 11 projects in the manual, they each have several variations to experiment with, and each covers a useful component.  Especially standout was the relay and shift register projects which were clearly documented and I haven’t seen them covered in other kits.
• Just the right skill level.  At least it was for me.  I think you’ll probably want to know at least a little bit of programming–any programming will do– and a very basic understanding of electronic components.  If you don’t have both of these I’d recommend the Getting Started with Arduino book which gets you up to speed pretty easily on both programming and basic electric theory.
• Great manual. What you’re doing, how you’re doing it, troubleshooting and extending what you’ve just done. It’s very concise, but it anticipates problem spots and documents them well.  For each project you get both circuit diagrams and graphics showing what should go where.
•  Digital footnotes.  If you feel that the manual doesn’t cover a subject thoroughly enough there are usually shortened URLs to more information, code examples, full Wikipedia  articles, and more.
• Nicely self guided.  You can do most chapters in 10-20 minutes to do most chapters.  Or half a day if you get curious and go exploring on your own. 
• Quality components.  They aren’t deluxe, but they’re not the cheapest they could have used.  And they didn’t need to include the nice parts box or the acrylic holder but they did.

You can get the kit here at the Adafruit store!