I have written sort of hello world of Arduino !. Blinking LED. Follow the excellent tutorials from ladyada.net.
Similar Boards.
At first I was confused between freeduino, sanguino, seeduino etc. These are all clones of arduino (There are many more. Checkout wiki).Although arduino hardware and software references are available opensource, the name "Arduino" should not be used in the derived works. So these boards often uses a name that ends with "duino". Often you find freeduino and sanguino. There is no difference between freeduino and arduino. Sanguino is a more powerful varient of arduino. You can find the difference between arduino, sanguino and arduino mega here.
Where to buy ?.
The board I got is from makershed. There are lot of starter kits available. Before buying any of these check out comparison of these boards here.
If you are in India then you don't have much options. Makershed is shifting the boards to India but the shipping cost is 25$. You can find freeduino and sanguino board from Bhasha e-store. It is Pune based company. The price of these boards is very less Rs 1000 (20$) and you can get useful components (including 16x2 lcd, breadboard and few more components) for about Rs500 (10$). This is the cheapest of all.
Useful links.
http://www.arduino.cc/
http://en.wikipedia.org/wiki/Arduino
http://www.ladyada.net/learn/arduino/
http://blog.makerbot.com/2009/03/27/arduino-vs-sanguino-vs-arduino-mega/
http://aaroneiche.com/2009/07/16/arduino-starter-rundown-part-2/
http://www.makershed.com/ProductDetails.asp?ProductCode=MSAPK
http://www.bhasha.co.cc/
