First of all, I would like to thank all the people here providing information and helped me.
It was quitely lucky today to get the ILR approved (main applicant + 2 Dependents) within 3.5hours. I would like to answer any questions if I can. The following is my documents' list and experience/tips.
Documents List:
Section A Identity Documents
A1. Applicant's Passport
A2. Spouse's Passport
A3. Baby's Passport
A4. BRP
A5. 3 x 2 photos
A6. Police Registrations (Pls note not every one have these documents)
Section B Relationship Documents including evidence of cohabitation (We dont have any documents with both of our names, therefore we provide quarterly documents respectively from 6 different resources for the evidence of cohabitation. The resources include GP letter, Council bill, utility bill, bank statement, Water bill, Police certificate)
B1. Baby certificate
B2. Marriage Certificate (Origional)
B3. Certified and Translated Marriage Certificate (again, not everyone need it)
B4. From Sep 2010 to Dec 2010 - Main applicant (Bank Statement Sep 2010)
B5. From Dec 2010 to Mar 2011 - Main applicant (Bank Statement Jan 2010)
....
B12. From Sep 2010 to Dec 2010 - Spouse (Bank Statement Oct 2010)
....
B19. From Jun 2012 to Sep 2012 - Spouse (Bank Statement Jun 2012)
Section C Life in the UK test
C1. Main applicant
C2. Spouse
Section D Tier 1 Points Scoring Assement documents
D1. Employer letter to confirm salary and employment information
D2. 12 months' payslips
D3. 12 month bank statement
Section E Other related documents
E1 5 year's P60
E2 Origional HSMP Letter
E3 Tier 1 approval letter
E4 Recent Bank statements
E5 Recent payslip
Actuall, it only took 30 minutes for caseworker to go through my documents and gave the approval decision. I do think the clearly documentation did help. I also provide the copy of all the documents and label them, but I did not provide a covering letter.
Tips:
1. Please do ask the staff if you confused what you should do next. They are all very helpful.
2. After your passports were checked at ground floor, you will be issued a reference number which is on the top of your receipt. We were a little bit nervous and did not notice since the dovetail clip covered it - silly one

Good luck to every one!