To begin with, you seem to be asking two separate questions here without distinguishing them.
One question is what procedures are required by ISO 20000 (a question that should also include which policies, formal plans, specific records, and specific roles are required).
That isn't really that hard to answer since a close read of 20000 would tell you that. The document is full of specific requirements ("shalls", maybe about 200, but they're hard to count due to overlaps and shalls with multiple references) but you only need to go through and pull out references to specific documentation requirements and you'll have answered it yourself. Even where the standard doesn't say you need a formal procedure it would be obvious enough where other processes need some framework document, call it a procedure, a process document, divide it between a policy and one of those, or however else.
A second question is where you could get sample procedures. In a sense that's easier because Google will turn up a lot but still difficult because most aren't that good, and identifying which are which is hard. Even if you could find a good template version of an entire ITSMS / 20000 system (the kind of thing consultants develop and sell for a lot) it would still need a ton of customization. Off-the-shelf procedures for very general processes need to become very specific to actual use (activities, records, roles, etc.) to be useful. It would basically be a distillation of ITIL practices, and it doesn't take much investigation there to figure out they are too general and there are too many for them to be useful directly.
Per other postings convention this is where I should recommend a general reference site link but IT service management is thin on those, at least good ones, with detailed background or procedure template references. Your best bet is a broad search and carefully combing through what turns up, along with referencing ITIL (IT service management practices).
The owners of ITIL, the British OGC, won't give away much for free but you can read some references, learn about training, and the glossary of terms they will provide is worthwhile:
http://www.best-management-practice.com/IT-Service-Management-ITIL/
COBIT is definitely not what you are looking for but it is worth a look:
http://www.isaca.org/Knowledge-Center/COBIT/Pages/Overview.aspx
FITS is a very simple version of an IT Service Management system (what a 20000 system is), not even close to enough to certify to 20000, and you can't cut and paste such a thing, but a good basic reference that shares documents and practice guidance:
http://www.thefitsfoundation.org/