Know-How Exchange : Advertising/PR

Hi everyone-
I'm doing some marketing for an online scrapbooking website. The company teaches online classes for using Photoshop and Photoshop Elements to scrapbook. The owner was asking me if it was worth using PR Newswire.

The company doesn't do any press at the moment. I just started working for them so I'm planning on reaching out to top scrapbooking sites to cultivate relationships with them. On the PR front though, the owner has a great story and is running a VERY successful business out of her home.

She is trying to attract people to her site who may not even know classes like hers are offered. For example, for the new mom who may want to start scrapbooking her children.

So my questions are...
- Will sending out press releases through a big news service help when it's such a niche industry? (possible releases include new online classes she just launched, a company who is growing even despite the economy, mom-entrepreneur who mostly runs her business at night, etc.) OR should I just focus on specific media outlets, blogs, etc.
- Will press releases help in her search engine rankings? If so, how?

Thanks for your help!
M