Answers to your Questions:
1. Petitioners who live in the following states or territories should file their Form I-751 with the California Service Center (CSC): Alaska, American Samoa, Arizona, California, Colorado, Guam, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, North Dakota, Ohio, Oregon, South Dakota, Utah, Washington, Wisconsin, and Wyoming. The mailing address for CSC is:
USCIS California Service Center
P.O. Box10751
Laguna Niguel, California 92607-0751
2. It is better to separate the checks application fee and biometrics
3. I would suggest to have a cover letter sample below:
USCIS California Service Center
P.O. Box 10751
Laguna Niguel, CA 92607-0751
RE: I-751 JOINT PETITION TO REMOVE CONDITIONS OF STATUS ON:
(K-1 VISA) Name of immigrant spouse, A#xxxxxxx
Dear USCIS examiner:
Enclosed please find a JOINT I-751 petition for removal of conditions of permanent resident status regarding my spouse, NAME, Please also find a check for $465.00, the fee for this form and $80 for biometrics fee. My spouse entered the US on a K-1 visa. We are happily living together and request that this petition be accepted for removal of conditions on the residence of my spouse, NAME
Enclosed also please find the following documents to verify the status of our marriage and ongoing relationship:
JUST ITEMIZED HERE THE DOCUMENTS YOU MAY HAVE.
Sincerely,
Name of the US Spouse
I hope this will help you.
QUOTE(sambridh @ Jun 27 2008, 08:04 PM)

I am ready to sent my I751 I have 3 quesations:
1) I live in State of Indiana where can I sent my I 751.....can i sent it by certified mail or USPS nextday service please advise.
2) How i can send a check I have to write 2 seperate check for petition and Fingerprint or i can send $ 554 in one check.
3) Do I have to write a cover letter or not.
Please advise me I am rookie over here.