As long as you have the installation cd, you just need to pop that into your cdrom drive once you get the new hard drive installed. Select new install and select the new drive as the installation partition.
Linux does have a great range of tools that are similar to most windows applications you would find, much of them are better then the MS versions. These programs include microsoft office, photoshop, not sure about turbotax; and they are fully compatible with one another so if you save a program on a windows computer, you can open it on your linux computer, and vice versa. For any not so popular apps that haven't been ported over to linux, you could use a program called WINE which lets you run any windows app inside of linux.
A fair word of warning if you do decide to delve into the world of linux. I've talked many very intelligent computer savvy people into switching to linux, only about 1% has actually gotten anything out of it. Of course if you ask anyone who knows anything about linux if its better than windows, then they will go on and on about security and stability and yada yada, but the reality is for the average every day end-user, windows has more than enough security and stability, and because it is more widely used windows is actually better for the average joe. If you're a power user then yes, you need linux, but if you were a real power user you would already be on linux, and you would call it unix, not linux.
So what was the point of that last schpiel? If you don't want to invest 20+ hours a week into relearning how to do the most basic functions on your computer, don't switch to linux. I WOULD NOT recommend switching to linux before getting your computer back up-and-running and restoring/backing up your old files as the learning curve may cause you to lose important files. Once you get your computer fixed and your files backed up, if you have extra free time and would like to learn the great wonders of linux, then install linux on a dual boot computer with windows already installed. This way you can learn linux when you have the time, but you would still have windows to fall back on when linux starts acting like a pain in the kernel. Let us know if you decide to do this and we can walk you through setting up a dual-boot computer, or installing a virtual machine to play with linux inside of windows.
That's my 2 cents, everyone else's opinion to follow...