There are Seven simple steps to succesful project management and they are straightforward to operate (although not necessarily simple).

Decide what it is you want to achieve and spend time deciding.

I can't think of any Project I have worked on where we have spent enough time deciding on what we wanted to achieve and how we wanted to achieve it.  Often business people don't value planning - they just want to get on with things and that's fine as far as it goes.  Spending time defining objectives and your strategy saves twice as much time later in the project, as often as not.  Whilst I would never advocate procrastination, trying to achieve that balance is part of the Zen of Project Management.

Ensure you have the resources to realistically delivery.

Maybe this is a little flipant, but if you have a 5k budget, you will not be the next facebook! Be realistic about what you can achieve.  Use your resources wisely

Measure it effectively and remain SMART

Specific, Measureable, Achieveable, Realistic and Timely.  I know people who hate SMART, but when managing projects, meaningful measurement makes for a happy customer.

Thinks about Risks.

Risks are things that may or may not happen to your project - both positive and negative.  Some risks are good and you might want to exploit them.  Most are bad and you want to mitigate them.  Be realistic.  Swine flu is unlikely to be a serious negative risk for a project - whatever the TV might say.  Unless of course you manufacture Tamiflu and it might be positive!

Don't hessitate to seek appropriate advice.

Now, I suppose you would expect us to say this, but I am going to surprise you - you don't always need consultants.  A problem shared is a problem halved.  Talking through issues with other people to garner their perspective can be very helpful, especially if you can find someone with an objective viewpoint.

Always make sure you are still delivering the benefits and they are still relevant.

It might sound like common sense (and most project management is), but would you continue a project to streamline a set of business processes when those processes are already obsolete?

Always keep track of the things you learned.

I am with Dante Alighieri - All hope abandon, ye who enter here!  "We must learn from our past, lest we be doomed to repeat it!" I don't need to say anymore, do I?

OK, there are many more things to achieve than that - Change Management is just one, and we'll cover these at another time.  But if you use the suggestions above, you are on your way to success.