Great! The main thing to watch out for is being sure that all parameters that should be localized in the Module are included in the list of the first argument so that nothing leaks out.

Give it a try and then post any questions and code attempts that you have and I or others will take a crack at advising your next steps.

Perhaps the best way to help you along your way with this is to point you to this tutorial:

http://www.wolfram.com/language/fast-introduction-for-programmers/interactive-usage/

And here is a tutorial on defining functions:

http://reference.wolfram.com/language/tutorial/DefiningFunctions.html

as well as two links that talk about how to localize variables:

http://reference.wolfram.com/language/tutorial/HowModulesWork.html

and

http://reference.wolfram.com/language/tutorial/ModulesAndLocalVariables.html

Once you have this under your belt you will be in a position to take the set of computations that are in your notebook, place them in a module to localize those variables that should not be exposed, and then create a function definition for those parameters that you want to supply as arguments to your function.