you can invite people for visit. you have to write invitation letter, stating purpose of visit. include copy of your work permit. T4 and paystub Forward this to your brother to support his visa application.
I did this when I was still in School, on study permit
Yes, You can apply for visitor visa for your family members while you are on Temporary Resident Visa working on a Work Permit either closed or open. I applied for my parents 4 months ago and they are here with me now. Most of friends (on temporary resident status) had their parents/brothers/sisters/in-laws visited them in Canada. Their stay is valid for 6 months only.
You can send an invitation letter and they have to send a request letter to CIC saying that they have strong family ties /economic background back home so that they would return back home after their authorized stay in Canada. The success rate is pretty much high.
your brother need to show some proof like he should be working or in school or there should be another reason so they will
convince that he is planning to come back...they reject the visa if they dont see any connection