You need to get an idea of how much you're talking about. In those taxable accounts, look for your "cost basis", or how much you've spent on purchasing those shares (and reinvested dividends). What you put in, versus what it's worth now, is your gain (could be a loss).
When you're figuring out what to sell, a typical preference is:
* sell losses first, since they help your taxes
* sell long-term assets (over 1 year) since they have a better tax rate (15% for the 25% bracket)
You have to decide if the gain is worth it to sell and pay taxes on, but looking up your cost basis is a good start.