Busted write every one of their songs, but sometimes they do have helpers, so I thought I'd explain who the other people are.

PROFESSIONAL SONGWRITERS

Steve Robson and John McLaughlin
These two produced the first album, and for some reason their names were added to the writing credits. James says they're now on bad terms, which is a shame.
Busted songs: Well.. apparently none, but they produced them.
Also written with: The Noise Next Door

The following three are from The Matrix, a trio of songwriters who got together in 1999.
Graham Edwards
Won an award at Songwriter Of The Year 2004. I can't find much about him, rawr.
Lauren Christy
Born in London. Studied at a Ballet school before realising she wanted to be a singer/songwriter. She recorded her own albums in the mid 90s on Mercury label. Married to Graham Edwards, they have one child, Georgia Christy Edwards.
Scott Spock
Played keyboards since he was 8 years old, also plays the trumpet. Now writes songs with the help of the computer.
Busted songs: She Wants To Be Me, 3am. Also produced the album.
Also written with: Avril Lavigne, Britney Spears.

Guy Chambers
CLICK for info.
Busted songs: Fake, Better Than This
Also written with: Natasha Bedingfield, Brian McFadden, Robbie Williams and lots more

Steve Powers
I don't really know much about him except he's a producer as well as a songwriter.
Busted songs: Fake. Also re-produced What I Go To School For for American release.
Also written with: Robbie Williams (or produced at least)

Mike Raphael
Guitarist in Neve.
Busted songs: Can't Break Thru
Also written with: Unknown, but I'm guessing Neve

Barry Gray
British musician who wrote the original Thunderbirds theme tune.
Busted songs: Thunderbirds Are Go
Also written with: Unknown

FAMILY/FRIENDS

Tom Fletcher
Guitarist/singer/songwriter in McFly, best friends with James.
Busted songs: Air Hostess, Crashed The Wedding, Who's David, Falling For You, That Thing You Do, Over Now, Loner In Love, Nerdy, Thunderbirds Are Go

Will Simpson
Charlie's brother, also in Brigade.
Busted songs: Why

Dougie Poynter
Bassist/songwriter in McFly.
Busted songs: Let It Go

Harry Judd
Drummer/songwriter in McFly.
Busted songs: Let It Go.