Internal auditing does not have to be complicated or a challenge. As Sidney Vianna pointed out, a lot of companies do internal audits because they have to. This also tends to lead them down the path of the old AS9101 checklist or some similar type of torture.
This of course feeds into the often hateful feelings toward internal audits by both "enlisted" auditors and the audit subjects.
IA's really only need to cover a few topics: What is the process being audited, What are the expected outcomes, What are the actual outcomes, Is the documentation a true reflection of the process being performed. An audit form for a small company should be 1-3 pages at most. The bulk of which should be notes referencing your objective evidence and findings. The rest of the information should come from your internal process docs/work instructions and work orders.
At the end of the day the purpose of IA's isn't to fulfill a requirement but to make the organization better. If you have a bunch of findings because the process does not match the documentation then you now have a reason to get the documentation moving forward. You also have a good sign that Doc Control may be an issue you need to look into further.