Your new Mac and many PCs or Laptops with Windows come with over thirty applications, so do you have everything you need? Your Mac software with the Leopard operating system or Windows should cover most of your basic needs, but you should think about increasing that capability. Depending on what you want to do.  Quicken is a great program for tracking your finances.  Windows computers are prone to virus attack so an anti virus program such as Norton or Mcafee are essential.

Office Applications.

Microsoft Office includes MS Word, Excel, and PowerPoint, so you have software for word processing, spread sheets, and presentations.  This suite is available both for Mac and Windows.  There are other software programs but to be able to share your work with others MS Office is essential.  There are different suites available, including one for students that is discounted.

iWork is Apple's suite of just 2 office type applications, Pages and Keynote. Pages is a full featured word processor and page layout program. It too can open and save Microsoft Word files. Keynote is a presentation program that rivals Microsoft PowerPoint. Both program's strengths are in creating good looking documents through graphic tools, templates and integration with other Apple applications like iPhoto and iTunes.

Pictures

IPhoto is a great tool for organizing and creating prints and projects from your digital photos, Adobe Photoshop Elements 4.0 has many of the common Photoshop tools at a much lower price than the full Photoshop.  I like to use JASC Paint Shop on Windows.

Where do I buy software? 

You can buy software direct from the manufacturer and download it.  There is no shipping cost that way, no waiting in line at the local computer warehouse store but you have to wait for the download.  For software you don't need right away, it makes good sense to shop online and compare prices, like on Amazon most things that I do not need right away.  Most major sites like Amazon have a slow free shipping option. I also find that even when I select the slow shipping option, you will get it usually in a couple days because most larger sites use distributed shipping locations which may be close to you.  You can shop Amazon from this page.  Other retailers such as buy.com offer great discounted prices on software, so shop and compare.