Wikipedia is not an academically citeable source. Any college student citing Wiki would get his work marked down. There are many reasons for this, and reliability is not the top one.
I would not recommend the IMC either - not because it is not a good website (we all know it's amazing), but because its author uses a nickname and because what it contains are oftentimes opinions presented as facts. There is, however, an exception - the IMC is a brilliant source of magazine interviews from throughout the band's career. It includes many hard to find interviews from the 1980s, for example, and its particular strength is that many are translated from French magazines, hence a unique source for these rare items.
The go-to sources are, apart from magazine interviews, the two official biographies (Running Free by Gary Bushell - a terrible piece of 80s tabloid journalism - and Run to the Hills by Mick Wall) and the history documentaries on the recent DVDs (contain some new revelations). You can also look for individual band member biographies or autobiographies, they exist for Paul, Bruce, Blaze and Steve, with varying degree of acclaim and quality. I can also recommend the book Infinite Dreams by Dave Bowler and Bryan Dray. It was written in the mid-nineties, but it is an interesting attempt at creating a Maiden biography based on magazine interviews embedded in the socio-historical context of the seventies and eighties. Any other publication I'm aware of is mostly either redundant as a source of information, or a random collection of anecdotes from people who were there somehow sometime.
However, I must admit that I don't know what a 'college project' is. Are you doing a presentation? A term paper? Something else?