Google is your friend. If you go to Google.com/linux then you will get only
Linux hits.

The Ubuntu site has loads of help. Go to help.ubuntu.com for Ubuntu specific
help.

Finally get your feet wet by getting a CD and running it from the Live CD
without installing. You can also install Ubuntu inside Windows with WUBI by
inserting the CD in while you are in Windows. It will then offer to install
Ubuntu to your C drive. This is not the best solution, but it will give you
a taste without partitioning your hard drive. Distrowatch.com has a list of
all of the top 100 distributions (there are now over 400). Most downloads
are free. You just need to download the ISO file and burn a CD from it.
See: https://help.ubuntu.com/community/BurningIsoHowto