Count the number of programs you use on a daily basis that are not web-based. You may come up with a list like this:
For many of the items on your list there will be a web-based equivalent:
MS Word> Google Docs or MS Office online
MS Outlook > Gmail
Photoshop > Pixlr, DevianrART muro, Sketchpad, Picnik or Sumo Paint.
Skype > imo.im (IM only), google talk (us only)
In each case, check out the web applications using Google chrome browser on your regular PC. Decide if it will meet your needs. If you're struggling to find a cloud alternative to an application you use, if you can't find anything with a search of the Chrome web store, post up on here and we'll try to help you . We're all doing the same thing, and the forum is a good place to exchange tips.
Next (and this one is a nice gotcha), check to see if you use any web applications that require Java. Things like: Minecraft, Screenr.com, gotomeeting. These won't work on a chromebook at all. You can spot them as they will prompt you to download/install/upgrade a Java program on your computer.
If there are a few things that you can't find a web equivalent for all is not lost - you can use a 'remote desktop' solution to access another computer from your Chromebook. There are a few solutions to this, my favourite of the moment is ThinVNC - it works just fine from the Chrome browser in Windows, and I'll soon report how it works on a Series 5 as soon as it arrives (should be Jul 1).
If you're concerned about leaving your home computer on all the time just in case you need it when on the road with your Chromebook, don't worry - you can probably setup 'wake on lan' which will allow you to turn it on remotely. I'm at early stages of playing with this too, but will report my findings when I get it running - although there are plenty of guides for this on the web.