How to create and store password hashes with Blowfish in PHP

1) How do you create secure Blowfish hashes of passwords with crypt()?

$hash = crypt('somePassword', '$2a$07$nGYCCmhrzjrgdcxjH$');

1a) What is the significance of "$2a"? Does it just indicate that the Blowfish algorithm should be used?
1b) What is the significance of "$07"? Does a higher value imply a more secure hash?
1c) What is the significance of "$nGYCCmhrzjrgdcxjH$"? Is this the salt that will be used? Should this be randomly generated? Hard-coded?

2) How do you store Blowfish hashes?

echo $hash;
//Output: $2a$07$nGYCCmhrzjrgdcxjH$$$$.xLJMTJxaRa12DnhpAJmKQw.NXXZHgyq

2a) What part of this should be stored in the database?
2b) What data type should be used for the column (MySQL)?

3) How should one verify a login attempt?