You will need 120 points to be satisfy the points pass mark on a Skilled Independent visa.
Assuming you are aged under 45, and have been working as a nurse for 3 out of the last 4 years, I would see your points position as being something akin to:
Occupation 60 points
Age (assume aged between 40 and 44) 15
English language competency 20
Specific work experience 10
MODL occupation (no job offer) 15
TOTAL 120 POINTS
If you are short of 120 points for whatever reason you should then consider a State Nomination (only 70 points are needed), and failing that a Skilled Independent Regional (Provisional) visa.
It may be worthwhile contacting a migration agent to discuss your position and your visa strategy ... that is probably first base before you embark on a skills assessment application.
In case of need:
http://www.gomatilda.com/contact.cfm#appraisal
Best regards.
__________________
Managing Director, Go Matilda,
http://www.gomatilda.com
Registered Migration Agent Number 0102534 and Chartered Accountant (England & Wales, and Australia)
Offices in the UK and in Australia