Any software you buy will have free tutorials and tonnes of info that will keep you reading for at least a year.
Then Sonar has the free videos as mentioned as well as some great homemade stuff by members here( see Fastbikerboys post ) .
You need to figure out if your a person who learns by reading or by watching or by doing. There is more written material than videos so you'll learn more by reading if that works for you.
One word of advice is to be careful of some Free "opinions" offered on the internet.
The best advice so far is to purchase a good audio interface along with the software.
Many interfaces will come packaged with a basic version of DAW software so I would recommend that route. Most are easily upgraded once you settle in.