Jay s answer is perfect if you are going to the east side of Canal Street, near Chinatown. If, for any reason, you want to visit the west side of Canal Street near the Holland Tunnel, you can also take the A, C, or E train to Canal Street (lets off near 6th Avenue).
There sure is.If you want to go on the West end of Canal St (it s right near the Holland Tunnel and 6th avenue), the A,C and E stop at Canal St.If you want to go to the East end of Canal St, you can take the N,Q,R, or W, the 6 ( the 4 stops at Canal St at night) and the J,M and Z also stop at Canal St.