If you are using SQL Server clustering, the cluster is active/passive, in that only one server in the cluster ever owns the SQL instance, so you can't split load across both of them.
If you have two databases you're using, you can create two SQL instances and have one server in the cluster own one of the two instances, and the other server own the other instance. Then, point connection strings for one database to the first instance, and connection strings for the second database to the second instance. If one of the two instances fails, it will failover to the passive server for that instance.
An alternative (still not load-balancing, but easier to setup IMO than clustering) is database mirroring: http://msdn.microsoft.com/en-us/library/ms189852.aspx. For mirroring, you specify the partner server name in the connection string: Data Source=myServerAddress;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;Failover Partner=myBackupServerAddress; ADO.Net will automatically switch to the failover partner if the primary fails.
Finally, another option to consider is replication. If you replicate a primary database to several subscribers, you can split your load to the subscribers. There is no built-in functionality that I am aware of to split the load, so your code would need to handle that logic.