is a good place to start for reiki 101 [basic info].
You can find a lot of info on reiki by doing a search and there are a number of free online groups at yahoo.
Suggest u check out Reiki_On, they are a good bunch and will do free level 1 & 2 attunements if you are suitable and pass the tests for each level.
You don't incidentally become a Reiki Warrior by doing any of this.
You will become a practioner [a healer] and will be able to help others and yourself. There is no such thing as a RW as far as I know! If you go down the same path as myself you can become a Reiki Master and be able to attune others to become practioners.