"H" is the code letter for St. Louis rather than the bill's series. The series letter on a bill (if it has one) is a small letter located next to or under the date. The first bill in any series does not have a letter; the second one is A, etc. so it can be a bit strange.
In any case your bill, regardless of series letter, is worth somewhere in the $22 to $28 range.
$12 to $15, assuming average wear.
As of 09/2008 auction prices are around $24.
No, only for the Federal Reserve Bank of Minneapolis
L is the Federal Reserve district letter. The series letter is next to the date, and will either be not present, or an A.
This is a Federal Reserve note and should have a green seal. They are worth $22-$30 in circulated condition and $40 or more in uncirculated condition.
$50
An A series in avg.condition is worth around $12.50.
"A" is the highest series letter for 1928 $50 Federal Reserve Notes. "K" is most likely the Federal Reserve District letter. The series letter, if any, on US bills is next to the date. Please see the question "What is the value of a 1928 US 50 dollar Federal Reserve Note?" for more information on values.
There were no series letters on any 1929-dated US bills. A large "G" indicates that the bill was distributed through the Chicago Federal Reserve District. There's more information at the question "What is the value of a 1929 US 5 dollar Federal Reserve Note?"
No, there are no half billion dollar bills out there! This is an old scam.
The series 2003 is similar to the 1996, but was made by the federal reserve because of the issues they were having with the 2009.
There were no series letters on any 1929 US bills. You may be referring instead to the Federal Reserve District letter; "G" indicates your bill was distributed by the Chicago district. There's more information at the question "What is the value of a 1929 US 100 dollar Federal Reserve Note?"