That is what they are used for, to send a letter to another place in the country.
A single First Class stamp (44 cents).
Assuming you are talking about a US First Class Stamp: No.
The cost of a Royal Mail first class stamp is 60p. The price of a Royal Mail second class stamp is 50p. A first class large letter stamp is priced at 90p. A second class large letter stamp is priced at 69p.
A single First Class stamp is adequate for a one ounce regular letter.
I depends on how much the letter weighs, 1 First Class stamp is good for 1 ounce.
One first class stamp currently 44 cents for the first ounce.
Four cents for a one ounce First Class letter.
In the UK, 1st Class stamp for a standard letter is currently 41p or 61p for a standard large letter (Jan 2011)
A first-class stamp is not the same as a forever stamp. A forever stamp holds the value of a first-class stamp regardless of how often the rate for first-class postage has increased. A first-class stamp only holds its face value.
No, it will not be sufficient postage.
What is the cost of a letter to be mailed from US to Canada
It should be delivered the next day with a First Class stamp.