By Train:

M train to Wyckoff Avenue, L train to Myrtle Avenue - both are at the same station which leaves you on the corner of Myrtle, Wyckoff, and Palmetto Avenues (a three-way intersection) one block away from Gates Avenue. 

By Bus:

B13, B18, B26, or B52 to Gates and Wyckoff Avenues.
B54 to last stop at Palmetto Street and Wyckoff Avenue - 1 block away from Gates Avenue.
Q55 or Q58 to Palmetto Street and Myrtle Avenue - 1 block away from Gates Avenue.
 

Brooklyn:

Via Highways take Belt Pkwy West to BQE East.  Take BQE to Flushing Avenue Exit.  Make a right onto Flushing Avenue and take Flushing to Bushwick Avenue.  Turn right on Bushwick.  Take Bushwick to Myrtle Avenue and make a left on Myrtle.  Take Myrtle to Gates Avenue then turn left on Gates Avenue.  Go one block to Wyckoff Avenue.  Coalition is the corner GreenPoint Bank building on the left hand side.
Via Local Streets take Kings Highway north.  The end of Kings Highway will turn into Howard Avenue. Take Howard Avenue north to Eastern Parkway.  Turn right onto Eastern Parkway.  Turn left at the intersection of Eastern Parkway and Rockaway Avenue.  Proceed north on Rockaway Avenue.  Rockaway Avenue ends at Broadway.  Turn left onto Broadway and take it to Gates Avenue.  Make a right on Gates and go eight blocks to Wyckoff Avenue.  Coalition is the corner GreenPoint Bank building on the left hand side.
From Downtown Brooklyn take Myrtle Avenue east to Gates Avenue and turn left on Gates Avenue.  Go one block to Wyckoff Avenue.  Coalition is the corner GreenPoint Bank building on the left hand side.

Take FDR Drive to Williamsburg Bridge.  Bear right and exit bridge onto Broadway.  Take Broadway to Myrtle Avenue.  Turn left on Myrtle and take it to Gates Avenue.  Turn left on Gates Avenue and go one block to Wyckoff Avenue.  Coalition is the corner GreenPoint Bank building on the left hand side.

Van Wyck Expressway South or Grand Central Pkwy to Jackie Robinson Pkwy.  Take Jackie Robinson Pkwy to Cypress Hills Street Exit.  Exit and turn right at traffic light onto Cypress Hills Street (winding road).  Take Cypress Hills Street to Cooper Avenue.  Turn left onto Cooper Avenue and continue to Wyckoff Avenue.  Turn right on Wyckoff Avenue and take it to Gates Avenue.  Coalition is the corner GreenPoint Bank building on the right hand side.
BQE West to Meeker/Morgan Ave Exit.  Turn left on Morgan Avenue and continue on Morgan bearing right.  At Flushing Avenue, Morgan Avenue turns into Wilson Avenue.  Take Wilson Avenue to Myrtle Avenue and turn left on Myrtle Avenue.  Take Myrtle to Gates Avenue then turn left on Gates Avenue.  Go one block to Wyckoff Avenue.  Coalition is the corner GreenPoint Bank building on the left hand side.

Take Hutchinson River Pkwy or Cross Bronx Expressway to Whitestone Bridge.  Bear right and take bridge to Van Wyck Expressway.  Take Van Wyck Expressway South to Jackie Robinson Pkwy. Follow Queens Jackie Robinson Pkwy directions from there.

Southern State Pkwy to Belt Pkwy to North Conduit Exit 17W.  North Conduit to Atlantic Avenue.  Bear right at end of North Conduit onto Atlantic Avenue and turn right at next block onto Logan Street.  Take Logan Street to Jamaica Avenue.  Turn left on Jamaica Avenue and take it to Highland Blvd.  Turn right on Highland Blvd and travel through Highland Park.  Bearing right at fork, take Vermont Place until the end.  Turn left onto Cypress Avenue.  Take Cypress Avenue to Gates Avenue.  Turn left on Gates Avenue and go two blocks to Wyckoff Avenue.    Coalition is the corner GreenPoint Bank building on the right hand side.
Long Island Expressway to Cross Island Pkwy South.  Cross Island to Grand Central Pkwy West/Triboro Bridge.  Grand Central to Jackie Robinson Pkwy.  Follow Queens Jackie Robinson Pkwy directions from there.

Holland Tunnel to Manhattan.  Take Canal Street to Manhattan Bridge.  Exit bridge and go straight on Flatbush Avenue 2 blocks to Myrtle Avenue.  Turn left on Myrtle Avenue.  Follow Downtown Brooklyn directions from there.
Lincoln Tunnel to Manhattan.  Go south to 34th Street.  Turn left on 34th Street and go east to FDR at the end of 34th Street.  Take FDR South to Williamsburg Bridge.  Follow Manhattan directions from there.
George Washington Bridge to Cross Bronx Expressway. Cross Bronx to Whitestone Bridge.  Follow Bronx directions.