Vaccinations and health: None required.

No visa required.

Documents to present:

1. A valid passport from your country of nationality (or an acceptable equivalent travel document).
2. A valid green card (or equivalent valid proof of your status in the U.S.).
3. A valid permanent resident card (form I-551).
4. You need official proof of your status as a lawful permanent resident of the U.S., such as one of the following
5. Foreign passport with an unexpired temporary I-551 stamp (also known as an Alien Documentation, Identification, and Telecommunications [ADIT] stamp).
6. Foreign passport with a printed notation I-551 temporary ("Upon endorsement serves as temporary I-551 evidencing permanent residence for 1 year") on a machine-readable immigrant visa when endorsed with a U.S. Customs and Border Protection admission stamp
7. Expired permanent resident card (Form I-551) with Form I-797 (Notice of Action) for Form I-751 (Petition to Remove Conditions on Residency) or Form I-829 (Investor's Petition to Remove Conditions on Permanent Resident Status) pending resolution
8. Expired Permanent Resident Card (Form I-551) with Form I-797 (Notice of Action) for Form I-90 (Application to Replace Permanent Resident Card [Green Card]) pending
9. Valid re-entry permit (Form I-327)
10. Form I-94 with an unexpired temporary I-551 stamp (ADIT stamp) and a passport-style photograph.

More information here.