However, there is an excellent book out there on Branding SharePoint 2010 and tons of helpful web sites that can get you through customizing what you need to. Some are here, here, and here.
As a general rule, I prefer to do all of my branding as a SharePoint feature in Visual Studio 2010 as that allows it to be easily deployed across multiple environments and minimizes the number of places where human error can be introduced. This works out well for me as most of my clients prefer very complicated and specific branding but that is certainly not the only way.
For what it is worth, if your branding initiative does require you to start with a new Master Page, I highly recommend using the starter master page on codeplex. It will save you hours of troubleshooting.