You can configure OWC to run your Virtual Instructor-Led Training events, or you could also use a third-party service like Adobe Connect, WebEx, GoToMeeting, etc. The advantage of using OWC is that it is integrated already and you don't need to schedule the details of the online meeting from a separate system and then manually map it to your Learning Object in OLM.
You can add external users as Customers and enroll them in Classes / give them access to Learner Self-Service. Alternately, you could also create a custom Applicant Person Type for Learners. The advantage of using the new Person Type is that you can group the Learners into Learner Groups and bulk enroll / bulk subscribe them to training. Also, if you think there's the possibility that the person could eventually become an employee, it will be easier to convert the record for the Applicant / Learner Person Type than it will be to convert the Customer record. Customers can only be added to Classes one at a time, but it may be the best choice if it's an external customer that you'll be charging for the training. If you're using a DMZ for iRec, the setup would be similar for the Learner Self-Service setup for these outside Learners to access the system.
I believe the functionality for integration with Financials (AR, GL, Projects, OM) is the same in R12 as it was with R11, so depending on your specific needs, you may need to customize it in the same way to meet your business requirements. I'm not aware of any documentation that exists outside of the standard Oracle documentation on this topic, but would also be interested if someone else has a link they could share.