The self-publishing industry is growing and becoming more credible all the time. With the Print on Demand technology that is available to authors through various publishing platforms the challenges of self-publishing are reduced to good editing, a great cover choice, and marketing. That said, these are no small feats, nevertheless. This is why authors that have real talent and a unique manuscript—that is in fact marketable—should still try querying an agent. This is the easier route in terms of real success if your work meets the criteria of good writing and a unique story. Also, some of the larger presses are bypassing agents and accepting open submissions. Google this to get more info.
I follow literary agents` blogs and if you are a serious author you should do so as well. This will allow you to get a feel for the market, the publishing industry trends, and what agents are looking for in general. As I look at new agents and old, I see a trend in terms of genres that are repeatedly mentioned in their bios or submission instructions. The two hottest genres are Memoir and YA. Of the two, YA is the hottest genre in the market at this point and I`m not sure why; however, I see a trend of more adult themes in the YA genre which seems contradictory, but hey, I don`t make the rules, I just study them.
Another much overlooked venue (and I think that POD and self-publishing contributes to this) for freelance writers is in the area of print and online magazines. There are a host of opportunities to get published and actually get paid in this particular market. Here is a fantastic site for magazines (both print and online) which accept open submissions: http://www.newpages.com/.
As for following good literary agents, I would encourage you to find the app called “Flipboard” and follow the “literary Agents” category. You will find the newest and most relevant information on this app, learn the ins-and-outs of the publishing industry, and remain aware of newest trends. I hope this helps—good writing wishes to you!