Bobby, if you want to connect from your mac osx to a sql server installed on a parallels vm you need to do 3 things:
1) Enable remote connections on your sql server.
Microsoft SQL Server 2005 -> Configuration Tools -> SQL Server Surface Area Configuration -> Surface Area Configuration for Services and Connections -> Database Engine -> Remote Connections -> Local and remote connections -> Enable TCP/IP -> Apply
2) Turn on the SQL Server Browser service (sql server express and dev edition turn this off by default)
Microsoft SQL Server 2005 -> Configuration Tools -> SQL Server Configuration Manager -> Start SQL Server Browser service
3) Configure the firewall to allow network traffic
You can configure it per program or I just opened a port in firewall exceptions (1433 by default for SQL Server 2005)
For instance my jTDS connection string looks like that:
jdbc:jtds:sqlserver://10.211.55.7:1433;DatabaseName=master
(where the host is your vm's ip of course)