United States citizens and legal permanent residents can sponsor close family members, including parents, spouses, children and brothers and sisters. Only the following categories are allowed:

Immediate relatives
Parents, minor children and spouses of US citizens

There are an unlimited number of visas available for immediate relatives, which means that you can apply for permanent residence at the same time you file the I-130 family petition. In Boston, the process normally takes about 7-9 months from filing to the interview and approval.

Preference categories
1st: single children over 21 of US citizens
2nd A: minor children and spouses of permanent residents
2nd B: single children over 21 of permanent residents
3rd: married children of US citizens
4th: brothers and sisters of US citizens

There are a limited number of visas for the preference categories, and more petitions pending than visas. This means that you may have to wait for a visa to become available after your visa petition is approved. The waiting time depends on the category. The Visa Bulletin put out by the Department of State lists the dates of the petitions that are currently receiving visas in each category. When your priority date (the date you filed the I-130 petition) becomes current, then you can apply for an immigrant visa or adjustment of status.