It's all on the CIC site: http://www.cic.gc.ca/english/immigrate/skilled/index.asp
But...
(Please note that this info does not apply to the Federal Skilled Trades Program)
1) Determine your eligibility by doing this CIC quiz http://www.cic.gc.ca/ctc-vac/ee-start.asp
2) Get your language test(s) done. You must get at least CLB 7 in each of the four sections for the Federal Skilled Worker (FSW), Provincial Nomination Program (PNP) or Canadian Experience Class (CEC) streams. But getting CLB 10 gives you maximum points for language.
How does CLB match back to the language tests? That info is here --> http://www.cic.gc.ca/english/resources/tools/language/charts.asp
3) Get your qualifications assessed by doing an Education Credential Assessment. Details here --> http://www.cic.gc.ca/english/immigrate/skilled/assessment.asp
4) Determine the code that best applies to you on the National Occupation Classification (NOC) list http://www.cic.gc.ca/english/immigrate/skilled/noc.asp
The occupation must be NOC 0, A, or B for FSW or CEC.
5) When you have those in hand you create your express entry profile. http://www.cic.gc.ca/english/immigrate/skilled/profile.asp and register for the Job Bank http://www.jobbank.gc.ca/home-eng.do?lang=eng
You'll be given points based on your age, education, number of years work experience, and language skills. The points system is detailed here --> http://www.cic.gc.ca/english/express-entry/grid-crs.asp
You'll be in a pool with thousands of other applicants http://www.cic.gc.ca/english/immigrate/skilled/pool.asp
Of course, the more points you have the better. The max is 1200, with 600 of those points coming from your ability to snag a PNP or a job offer with a very hard to get Labour Market Impact Assessment http://www.cic.gc.ca/english/work/employers/lmo-basics.asp
For CEC applicants, the max is 600 but someone who has no work experience in Canada who is only eligible for FSW can only get up to 520 points.
6) Finally, wait for your invitation to apply (ITA). But in the interim you will need to do the following:
a) Have your application fee (C$550 each for principal applicant and spouse) and right of permanent resident fee (C$490 each for principal applicant and spouse) ready
http://www.cic.gc.ca/english/information/fees/fees.asp
b) Identify how you will provide proof of funds http://www.cic.gc.ca/english/immigrate/skilled/funds.asp
c) check out what is required for the police certificates http://www.cic.gc.ca/English/information/security/police-cert/index.asp
d) find out how long it takes to get a date for the medical exam. http://www.cic.gc.ca/english/information/medical/medexams-perm.asp
e) contact previous and current employers about them providing job letters. You must have at least 12 months of full-time, or an equal amount in part-time, skilled work experience. Full-time work means at least 30 hours of paid work per week. Work experience while you were a full-time student does not count.
f) research cities in the province(s) where you want to live.