A friend sent me an email this morning:
I want to buy a mac laptop, but I do not want to pay a ton getting the software I just bought (ie photoshop, microsoft office, etc) to be compatible with a mac. What is the best route for me to go about doing so?
Good news! There are a lot of options, and a lot of them are outlined well on Apple's Get A Mac spiel. Here's the important stuff.
Run Windows on Mac
Here's an easy one. You can either install Windows as a dual-boot with Boot Camp (meaning that you reboot your computer to switch between using Mac OS X or Windows) or run Windows directly on your Mac's desktop using Parallels Desktop or VMWare Fusion (both of which are $79). But remember that when you run Windows you still have to deal with its issues, like viruses and Windows Update. More from Get A Mac
Mac version of Office
The Home/Student version of Office:Mac 2008 costs $130 on Amazon. The interface is much easier than any version of Office version for Windows, and I've never had an issue with document compatibility. More from Get A Mac
Forget Office and switch to iWork
Or, you can forget Microsoft altogether and move to Apple iWork for $79. iWork is much easier to use and produces way nicer looking documents and spreadsheets. iWork even opens and saves regular Office documents, usually very well, but not always perfectly. Unless you working in an office or school environment where you have to edit other people's documents, iWork is a great way to go.
Photoshop and other Adobe Products
You can call Adobe and they will switch your Photoshop license from PC to Mac and send you new discs. There might be a small fee ($20 or something?) but it is minimal and quite worth it. Running Photoshop natively on a Mac is an experience of its own.
Memory, or RAM, is very important to Mac OS X. Make sure your computer has enough, especially if you decide to run Windows as well. Virtually everyone will want 2GB and some will even want 4GB. But I don't recommend that you buy it from Apple as it's very expensive. Nowadays 4GB of good (working) RAM costs less than $80! And check out how easy it is to install on a MacBook.