Very easy to get from La Guardia airport (LGA) to anywhere in NYC … The Port Authority has a very convenient page on their web site … also see the handy page at CitiDex that includes driving directions and parking info, and all the ground transportation options such as city bus, taxi, train, and shuttle …
To get to mid-town Manhattan (1) take the M60 bus, which stops at all terminals (get a $2 MetroCard and get a free transfer to the subway) … (2) take a shuttle (between $8 and $22)… (3) if you have plenty of money to spend ($35 – $45, including tolls), hop into a taxi …
With the M60 bus, you can travel to and from La Guardia from the West Side (stops in front of Columbia University at the last stop). The M60 runs between 106th St and Broadway in Manhattan and La Guardia Airport from approximately 5 am to 1 am, seven days a week – schedule here in pdf. The M60 serves all airport terminals. Connections can be made with all north-south Manhattan subway lines … This is a grand-view ride across the Triborough Bridge to 125th Street and Lexington Avenue (i.e., Harlem) and free-transfer to the IRT #4 or #5 subway downtown to Grand Central … about half hour for the trip …
The MetroCard has many great features … such as: a free transfer between a bus and subway or vice versa within a 2 hour period … ride costs 20% less when you buy a Pay-Per-Ride MetroCard worth $10, $20 or more … $7 for the one day fun pass, $21 for seven days and $70 for 30 days …
Subway interactive map | schedules | HopStop
AGINY good value