It's tough looking for work when you have SA, 'cos all the things that you have to do (application forms, speaking to Human Resources people, phoning up strangers with requests, interviews etc.) are all things that tend to trigger SA.
It's a bit easier these days - lots of job adverts have 24/hr answerphones - so you can just leave a message (write down on paper first what you want to say). Some adverts let you download a form from the 'net, and apply online. Find where the ads tend to appear for the type of job you're looking for - most papers have special sections for different sectors on different days, e.g. Guardian has education jobs on Tuesday, social work on Wednesdays.
Probably answering ads is easier than "cold-calling". But if you do cold calls, write down some notes first before you begin, so at least you won't get flustered at the beginning.
The 'net is also good for researching the company or organization you're interested in. Try to get a feel for the place by browsing their website. Try to think of a couple of questions you can ask when you go for interview.
Once you get into a place for an interview or meeting, remember to focus outwards (and don't focus on your internal anxious feelings), take deep breaths to get more relaxed, remember to smile (flash a smile to everyone - receptionist, secretary, person who shows you around) because often they might have a small input regarding candidates.
In the interview smile, maintain eye contact with the interviewers, focus externally, try not to ramble (a short answer is better than rambling ...), if you don't know the answer then be honest about it and say you're willing to learn.
Good luck!
