The Rosetta Stone Hebrew Language interactive software is undeniably one of the best approaches to learn how to speak Hebrew alone.
The interactive lessons are much more interesting and thus easier to stick with than learning from a book. Although designed for adults, many homeschooling parents use this company's programs to teach their children foreign languages with great success.
The one complaint you may hear about the course is that it lacks any sort cultural content. This is true – you won't learn much about Israel or Jewish culture from this program, but you will learn to speak Hebrew.
What blew me away about this program is that it can actually rate your Hebrew pronunciation and accent!
In addition, the program allows you to display written Hebrew text either with the full vowelization (which is helpful to learn pronunciation) or without (which is how you will usually see Hebrew written).
This is a great feature that I haven’t seen in any other program.