Rachel,

The GUI is highly customizable. Even if you don’t spring for Shapeshifter, you can make a lot of the bouncing/zooming go away in basic System Prefs. You can make the Dock vanish. You can shrink your icons and set your background to a boring, basic grey if you like. 🙂

One of the things that always made me resistant to switching was the misapprehension that I’d be a slave to my mouse. Simply not true. Probably the number one thing you’ll want to learn on OS X are the myriad keyboard shortcuts that make day-to-day life on a Mac so much easier. Some are self-explanatory and similar to their Windows counterparts — Command-S for Save, Command-Q for Quit, Command-Tab to switch between apps, etc. — but some need a little more digging (and are far more useful).

FTP – Transmit, hands-down. Can’t beat the Synchronize feature.

Family Trees – This is something I’m just stepping into, and I’ve found TreeTracker to be a decent, if somewhat flawed solution. There are probably more expensive solutions out there that I’m too cheap to explore.

CSS – I use BBEdit, which is basically just a syntax-colored text editor (I’m old-school). I’ve also heard good things about skEdit, CSSEdit and Tag.

Finance – Never having used Quickbooks, I can’t make a specific recommendation, but I’ve found a combination of Studiometry (for business finance) and iBank (for personal finance) to serve my needs well.

OS X has a very active application development community. There are countless other tiny apps I use in various forms to make my day easier — too many to mention, but there’s one OS X app iin particular that absolutely rocks my world…

Quicksilver (free). It’s difficult to explain what Quicksilver does, except that it keeps most of the contents of your computer within reach of a few keystrokes. It has done more to vastly increase my speed and productivity than any application on any platform.

There’s many better explanations on Quicksilver’s amazing wonders from MamaMusings and 43 Folders.