a) you have to hold the bond for 5 years. If you redeem after one year, but before 5 the you forfeit 3 months worth of interest.
b) the rate changes by about 3%+the cpi. It is hard to predict changes in inflation. Bernake is targeting 2% which would give a return of around 5%.
c) you can buy bonds in demoninations of as little as $25
d) you buy and sell complete bonds. It isn't as easy to get in and out like a savings or checking account. The bond is like a complete item. You can't sell a piece of it. (well this kind anyway) Picture buying a sub and then selling the sub when it become more valuable. You can't sell just part of it.
e) as stated, in order to not incur penalties, you must keep it for one year.
f)
http://www.treasurydirect.gov
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another alternative for you may be a high-yield savings account.
http://www.emigrant-direct.com pays a little over 4% monthly and it is an actual account. It is more liquid and you can get in and out a little easier. No minimum balance and no transaction fees. They are a real deal bank. Only problem is that it takes several days to transfer the money in and outof your account.