The best qualifications are CELTA or Trinity CertTesol. Salary ranges between 17-25k roughly, depends where you teach (since you have no experience I imagine a learning centre would be less daunting to begin with than local school/kindergarten). Read all contracts carefully, check annual leave, working hours, sick leave details as a lot of people come here, get a job and visa sponsorship only to find their jobs unbearable. Good luck and try to talk to other NETs working at the establishment you apply to before signing the contract.