These are the steps I followed to get Hadoop install on my Windows8 Laptop. It takes 2-3 hours including the downloads for each step. Use latest software available.
3. Create a new Virtual Box to create the Ubuntu install
-- your Ubuntu install is ready to be used for any purpose
4. Use below blog to setup Hadoop on Ubuntu
If you face difficulty at any step, please reply on thread, I can try to pitch-in. Of course, Google search is best place to find any info. (Lot of help available for Ubuntu/Hadoop)
Cheers
~nirav