Here is a page on the US treasury notes
Regarding how to purchase:
You can bid for a note in either of two ways:
- With a noncompetitive bid, you agree to accept the yield determined at auction. With this bid, you are guaranteed to receive the note you want, and in the full amount you want.
- With a competitive bid, you specify the yield you are willing to accept. Your bid may be: 1) accepted in the full amount you want if your bid is less than the yield determined at auction, 2) accepted in less than the full amount you want if your bid is equal to the high
yield, or 3) rejected if the yield you specify is higher than the yield set at auction.
To place a noncompetitive bid, you may use TreasuryDirect, a bank, or
To place a competitive bid, you must use a bank or broker.
Once you buy the note the price you can sell it for will move depending on what interest rates are doing during those 10 years.
The price and interest rate of a Note are determined at auction. The
price may be greater than, less than, or equal to the Note's par
amount. (See prices and interest rates in recent auctions.)
The price of a fixed rate security depends on its yield to maturity
and the interest rate. If the yield to maturity (YTM) is greater than
the interest rate, the price will be less than par value; if the YTM
is equal to the interest rate, the price will be equal to par; if the
YTM is less than the interest rate, the price will be greater than