"He breathed on them and said 'recieve the
Holy Spirit.'" - John 20:22
"And there appeared to them parted tongues, as it were of fire: and it
sat upon every one of them and they were all filled with the Holy
Ghost" - Acts 2:3-4
Below are articles regarding The Holy Ghost.
Catholic Teaching on Holy Spirit
Synopsis on The Holy Spirit. Lots of Info.
Information on the Holy
Spirit on the Catholic Encyclopedia.
Article about the Holy