The requirements are known so you have an easy starting point, ensuring your hardware is 64-bit as:
- SharePoint Server 2010 will be 64-bit only.
- SharePoint Server 2010 will require 64-bit Windows Server 2008 or 64-bit Windows Server 2008 R2.
- SharePoint Server 2010 will require 64-bit SQL Server 2008 or 64-bit SQL Server 2005.
If it is not, you will at some point need to move it. A great place to start the process of learning is on Technet, Migrate an existing server farm to a 64-bit environment (Office SharePoint Server 2007)
Things can get complicated after that point. Do you have an existent environment?
- Deploy Service Pack 2 and take a good look at the SharePoint 2010 Upgrade Checker that is shipped as part of the update. The Upgrade Checker will scan your SharePoint Server 2007 deployment for many issues that could affect a future upgrade to SharePoint 2010.
- Get to know Windows Server 2008 with SharePoint 2007, this post is a great starting point.