On November 5, 2000 a company sold gift certificates totaling $3,000. By December 31, 2000 all but $750 worth of these cerfiticates had been redemed for merchendise. Outstanding cerfticates were then redeemed by January15, 2001.
How to record these transactions?

The Nov 5 transaction will be posted as: Debit Cash for the amount of cash received, Credit a Liabilitiy Account (probably Unearned Sales Revenue or similar account) for the amount.

Dec 31: Debit the Liability account for the amount redeemed ($3,000 - the remaining balance), Credit Sales Revenue for the amount

Jan 15, similar to the Dec 31 transaction except the amount will be for the balance remaining in the liability account.

The Nov 5 transaction will be posted as: Debit Cash for the amount of cash received, Credit a Liabilitiy Account (probably Unearned Sales Revenue or similar account) for the amount.

Dec 31: Debit the Liability account for the amount redeemed ($3,000 - the remaining balance), Credit Sales Revenue for the amount

Jan 15, similar to the Dec 31 transaction except the amount will be for the balance remaining in the liability account.

How would the gift certificates be reported on balance sheet December 31 ?

The $750 is what is remaining in your liabilitity account and is listed as a Current Liability as Unearned Sales Revenue or other similar account name