http://www.newsroom.lds.org/ldsnewsroom/eng/news-releases-stories/popular-turn-of-the-century-census-now-free-online

Please go to the above link to read the article about the 1900 U.S. Federal Census.  The Church of Jesus Christ of Latter-Day Saints has worked hard with all of it's volunteers to make this Census available to everyone for free!   

10,000 Volunteers Needed!  The Church of Jesus Christ of Latter-Day Saints is looking for some great men and women that can read both Spanish and English to help index the 1930 Mexican Census.  This is a HUGE project with HUGE BENEFITS! 

Some of the information that can be obtained on the 1930 Mexican Census is a persons name, age, religion, their relationship to others in the household, birth place and occupation.  That is priceless information for relatives that are researching their family history! 

1930 U.S. Federal Census

1) Line number.
Place of Abode:
2)  Street, avenue, road, etc.
3)  House number (in cities or towns).
4)  Number of dwelling house in order of visitation.
5)  Number of family, in order of visitation.
6)  Name – of each person whose place of abode on April 1, 1930, was in
 this family.  Enter surname first, then the given name and the middle initial,
 if any.  Include every person living on April 1, 1930.  Omit children born
since April 1, 1930.
7)  Relation – Relationship of this person to the head of the family.
Home Data:
8)  Home owned or rented.
9)  Value of home, if owned, or monthly rental, if rented.
10) Radio set.
11) Does this family live on a farm?
Personal Description:
12)  Sex
13)  Color or Race
14)  Age at last birthday.
15)  Marital condition.
16)  Age at first marriage.
Education:
17)  Attended school or college any time since Sept. 1, 1929.
18)  Able to read and write.
Place of Birth – Place of birth of each person and parents of each
person enumerated.  If born in United States, give state or territory.  If
of foreign birth, give the country of birth. See Instructions for
additional entries required for certain countries.:
19)  Person
20)  Father
21)  Mother
22)  Line number.
Mother Tongue (or native language) of foreign born:
23)  Language spoken in home before come to the United States.
Code-(For office use only.  Do not write in these columns):
24)  State or M.T. (A)
25)  Country (B)
26)  Nativity (C)
Citizenship:
27)  Year of immigration to the United States.
28)  Naturalized or alien.
29)  Able to speak English.
Occupation and Industry:
30) Occupation-Trade, profession, or particular kind of work, as spinner,
salesman, riveter, etc.
31) Industry-Industry or business, as cotton mill, dry goods store, shipyard,
public school, etc. 
Code (For office use only.  Do not write in this column):
32)  Class of Worker
Employment-Whether actually at work:
33)  Yes or No.
34)  Line number for unemployed.
Veterans-Whether a veteran of the U.S. military or naval forces
mobilized for any war or expedition:
35)  Yes or No.
What war or expedition.
37)  No. of farm Schedule.

1920 U.S. Federal Census

1) Line number.
Place of Abode:
2)  Street, avenue, road, etc.
3)  House number or farm.
4)  Dwelling Number.
5)  Number of family, in order of visitation.
Name – of each person whose place of abode on January 1,
1920, was in this family.
7)  Relation – Relationship of this person to the head of the family.
Tenure.
8)  Home owned or rented.
9)  If owned, free or mortgaged.
Personal Description:
10)  Sex
11)  Color or Race.
12)  Age at last birthday.
13)  Single, married, widowed, or divorced.
Citizenship:
14)  Year of immigration to the United States.
15)  Naturalized or alien.
16)  If naturalized, year of naturalization.
Education:
17)  Attended school anytime since Sept. 1, 1919.
18)  Able to read.
19)  Able to write.
20)  Line Number.
Nativity and Mother Tongue – Place of birth of each person and
parents of each person enumerated.  If born in United States, give
state or territory.  If foreign birth, give the place of birth, and, in
addition, the mother tongue.:
21)  Person
1) Place of Birth
2) Mother Tongue
22)  Father
3) Place of Birth
4) Mother Tongue
23)  Mother
5) Place of Birth
6) Mother Tongue
Occupation:
24)  Able to speak English.
25)  Trade, profession, or particular kind of work done.
26)  Industry, business, or establishment in which at work.
27)  Employer, salary or wage worker, or working on own account.
28)  No. of farm Schedule.

1910 U.S. Federal Census

1)  Line number
Location:
2)  Street, Avenue, Road, etc.
3)  House number or farm
4)  Dwelling Number
5)  Number of family, in order of visitation
Name of each person whose place of abode on April 15, 1910, was in this
family.  Enter surname first, then the given name and middle initial, if any. 
Include every person living on April 15, 1910.  Omit children born since
April 15, 1910.
Relation:
6)  Relationship of this person to the head of the family.
Personal Description:
7)   Sex
8)   Color or Race.
9)   Age at last birthday.
10) Whether single, married, widowed, or divorced.
11) Number of years of present marriage.
Mother of how many children:
12) Number born.
13) Number now living.
Nativity:
Place of birth of each person and parents of each person enumerated.  If
born in the United States, give state or territory.  If foreign birth, give the
country. 
14)  Place of birth of this person.
15)  Place of birth of Father of this person.
16)  Place of birth of Mother of this person.
Citizenship:
17)  Year of immigration to the U.S.
18)  Whether naturalization or alien.
19)  Line Number.
20)  Whether able to speak English; or, if not, give language spoken.
Occupation:
21)  Trade or profession of, or particular kind of work done by this person.
22)  General nature of industry, business, or establishment in which this
person works. 
23)  Whether an employer, employee, or working on own account.
If an employee:
24)  Whether out of work on April 15, 1910.
25)  Number of weeks out of work during 1909.
Education:
26)  Whether able to read.
27)  Whether able to write.
28)  Attended school any time since Sept. 1, 1909.
Ownership of Home:
29)  Owned or Rented.
30)  Owned free or mortgaged.
31)  Farm or house.
32)  Number of farm schedule.
33)  Whether a survivor of the Union or Confederate Army or Navy.
34)  Whether blind (both eyes).
35)  Whether deaf and dumb.

The 1900 U.S. Federal Census has increased in information again! 

1) Line Number
Location:
In Cities:
2) Street
3) House number
4) Number of dwelling house in the order of visitation.
5) Number of family, in the order of visitation.
Name – of each person whose place of abode on June 1, 1900 was in this
family.  Enter surname first, then the given name and middle initial, if any. 
Include every person living on June 1, 1900.  Omit children born since
June 1, 1900. 
Relation:
6)  Relationship of each person to the head of the family.
Personal Description:
7)  Color or Race
8)  Sex
Date of Birth:
9)   Month
10) Year
11) Age at last birthday
12) Whether single, married, widowed, or divorced.
13) Number of years of present marriage.
14) Mother of how many children.
Nativity:
Place of birth of each person and parents of each person enumerated.  If
born in United States, give state or territory.  If foreign birth, give the country.
15) Place of birth of this person.
16) Place of birth of Father of this person.
17) Place of birth of Mother of this person.
18) Line Number
19) Year of immigration to the U.S.
20) Number of years in the U.S.
21) Naturalization
Occupation, Trade, or Profession – of each person Ten Years of age
and over.
22) Occupation
23) Months not employed
Education:
24) Attended school (in months)
25) Can read
26) Can write
27) Can speak English
Ownership of Home:
28)  Owned or Rented
29)  Owned free or mortgaged
30)  Farm or house
31)  Number of farm schedule