Help! 140填表

I searched this forum, unknowspace, and immigration portal, but did not find much information on how to fill I-140 form. The instruction for I140 form from USC IS is not clear and detail for self-petitioner. Could some NIW DIY experts generously help?
Here I will type what I do for my I-140 form, please correct me if I am wrong. I believe your kind help will benefit a lot of DIY persons, including me. Perhaps someone will think these questions are too simple and basic, but why not let us work together and make it easy for following DIYers?

Part 1. Fill out name, address, city, state, country, zip code, SSN, email address.
Leave blank for Company or Organization Name, Suite#, Attn:, IRS Tax #.

Part 2. Check box i

Part 3. Fill out personal information. Not sure what is A#, I leave it blank.
One question may arise from item Date of Arrival and I-94# for those who enter U.S multiple times. I think the information appeared on the latest I-94 should be used.

Part 4.
1. check box “alien is in the U.S….”, type P.R. China in the following box.
2. address in China
3. leave blank or N/A
4, 5, 6, check box No, for people who did not apply I-140 previously and are legally stay.

Part 5.
1. check Self
2. leave blank
3. I have question. As currently a Ph.D student (I probably will graduate at the end of this year), I leave blank for Occupation and Annual Income. Gurus, especially NIW student self-petitioner, please shed light on this.

Part 6. Leave blank for all questions for student petitioner? Who has employer, need to answer these questions.

Part 7. Enter information of spouse and children.

Part 8. write signature, tel#, email, name and date.

Part 9. leave blank.
Thanks and bow.
cr