I work as "bank staff" to cover sickness etc and have no set wages.Entitled 2 Housing benefit and JSA?

I have been offered a job as Sessional Support Worker. Support Worker for this company is my ideal job so I was delighted after having been unemployed for a few months. However the work is completely unreliable. I have no idea how many hours I'll get each month. I am hoping I get quite a few but I have to be prepared that if I am not getting any hours I will simply not be able to live. I have no savings. I need �60 a week to pay my bills and �50 a week for everything else as a bare minimum. Thats 11 hours of work a week which I am pretty sure I won't get. What benefits am I entitles to? My friend thinks I might be entitled to JSA as I am working under 16 hours a week and also Housing benefit. However my salary is varied and so there is no way to PROVE I am taking home a low wage each month.