Newbie: What do I need?

I've been curious about Arduino for quite some time, but just recently decided to take the plunge. By chance, I found an Uno clone (OSEPP) at my local electronics store, so I bought it along with some components. The next day I found an Uno and some other parts on craigslist and purchased, so this is what I have:

Arduino Uno
Basic Stamp Microcontroller
2 Parallax Xbee Wireless Kits (Still in the blister packs and each has 2 Xbee 802.15.4 embedded antenna modules, USB adapter and 5V to 3.3V adapter)
2 Bread Boards (and jumper wires)
10 green LEDs
10 red LEDs
10 Yellow LEDs
10 100 Ohm resistors
10 110 Ohm resistors
10 150 Ohm resistors

I would like to set myself up with a nice selection of modules and components, so I can power my way through a couple of books without having to stop and go buy this or that component (although I realize this is still may happen).
My original thought was to buy the Ultimate Microcontroller Pack from MakerShed, but then I found this:

It seems like a great deal, although money is less important than getting what I need.
I realize this is a pretty broad question, but should this cover most beginner projects?
Does anyone have experience with this vendor? (The only complaint I've found was 'language barrier'.)

Thanks in advance for your help,

That seems to give you yet another processor (you have two Unos and a Stamp already).

One or two processors (which you have now) should be enough to get quite a bit done. I would be looking at stuff like switches (push button or toggle) and maybe some sensors like light-detecting transistors or light-dependent resistors.

Also maybe a little piezo speaker to make sounds with. Maybe some little motors. Depends what your interests are a bit. With an IR transmitter and an IR receiver you could make a "universal remote".

I would start making stuff, rather than trying to predict today what direction your interests may go once you get into it.

Thanks for your reply!

I was really looking at it in terms of the modules and components it came with (Here's a breakdown of the components: Arduino Workshop Components Package-2 - (The extra processor is just a bonus. It's the same price as the "Ultimate" MakerShed kit which comes no processor.) I have started making stuff (or at least doing the projects in the books), but tonight I'll be making by 3rd trip to the electronics store in the last 3 days. I would like to sit down with a book and finish 3 or 4 (very simple) projects without having to stop and go to the store. I'm an electronics neophyte, so I'm not great at anticipating my needs (unfortunately, neither book I bought gives you any sort of master parts list). Not to mention that buying the resistors, leds, switches, etc. locally can be up to 10x online prices.

I agree motors would be good, but I shouldn't have any problems sourcing motors from discarded electronics in my garage.

Thanks again for the quick response!

Hi EastDallas,
My wife bought me the Sparkfun Inventors kit my birthday last year and it was a good starting point for me. They have lots of other interesting looking bits I would love to get my hands on but shipping costs and customs duty prohibit.

Thanks for the reply, Riva.
That looks like a great kit, but I discovered that Radio Shack sells Arduinos, so I went to the nearest location yesterday and bought the Maker Shed Ultimate Microcontroller Pack. It was the same price as online, and no shipping.

Thanks again,