A laddering schedule can go like this:
Buy your CD's in 3 month increments
- 3 month
- 6 month
- 9 month
- 1 yr
As the 3 month matures, reinvest it with a 1 yr.
and so on with the 6 and 9 month CD's
After your first year you have 1 year CD's that mature quarterly, each in turn.
This allows you 4 opportunities to cash out without penalty every year.
You can repeat the pattern with 2 yr, 3 yr, 4 yr, and 5 yr CD's.
But short term rates are not much better then long term rates right now (because we currently have
http://www.investopedia.com/terms/i/invertedyieldcurve.asp">an inverted yield curve which you can see
http://finance.yahoo.com/bonds/composite_bond_rates">here and is often a harbinger of a recession) ...Anyways, I've seen 3 month CD's out there for 4.5% which makes it hard to appreciate the extra 1/2 point you get for a 5 year commitment.
Based on that info I'd advise you keep your time commitments short.
As for rates...
Here's comparative rates for 1 year CD's from bankrate:
http://www.bankrate.com/brm/rate/high_ratehome.asp?params=US,416&product=15