Occasionally I come across a good programmer that I could use to do some projects for me. I have lots of ideas and need help sometimes. I wondered if it's allowed to hire someone?
You should go the the Stack Overflow Careers specific site to hire people :
It is not a good idea to try hire people within the questions and answers site by leaving comments. That's not what the comments are meant for. Though, if you find the person's email on the profile, well then you can contact it. The profile is public, so if someone leaves their email, it's okay to communicate with them.
Assuming you have a legitimate project, and you're not filling answer comments with job solicitations, then
Go for it
I got hired in my current—dream—job after my current employer went to my profile, browsed to my website, found my email address, and contacted me.
Not that I'm an expert at this , but the right kind of work and money usually gets things done in the world of IT. I'm assuming you are talking about IT work , considering you want to hire a good programmer. Also you might need to be specific about what kind of skills are you looking for.