The process so far hasn't been quite as straightforward as I would have liked. I was able to read all of Tor.com and Strange Horizons for free online, or rather by saving individual stories to the Read Later tab on Safari; I could probably have done the same for Clarkesworld, but opted instead to buy individual issues through iTunes. (NB one alternative that I have used in the past is to cut and paste stries from web pages to Evernote, which then makes them available across all my devices, but that risks losing formatting.)
Asimov's was much more difficult. After much wrestling with the website, I failed to find an easy way of getting back issues in any of my preferred electronic formats, and in the end, advised by "Mark" from File770, downloaded each issue to the Newsstand app on my iPad. Not expensive at all, but also not ideal; I found the font size just a bit too small to be comfortable, and that may have affected my judgement.
Subterranean Press was much the most difficult. Its online catalogue gives no hint whatsoever about dates, so it's impossible to look for 2015 publications per se. Fortunately the Locus guides to forthcoming books and books already published in 2015 came to the rescue, helpfully informing me that only two novellas have been separately published so far this year, and only one more was planned at that stage (now published, I believe).
But then actually getting hold of the novellas in legitimate electronic format proved impossible. Amazon.com and Barnes & Noble both informed me that the books are not available in Kindle or Nook format, presumably because I am in Belgium rather than the USA. And my wallet balked at paying the equivalent of the price of four paperbacks from my local English language bookshop to get hard copies of two novellas. In the end I was able to locate DRM-free copies of both and read them that way. But I'd rather have paid the fair price for the ebooks (and will still do so if it is made possible). It also strikes me that if they are so difficult to get hold of, they are unlikely to have been read by many people with Hugo nominating power.
Anyway, having gone to the lengths of acquiring Jacaranda by Cherie Priest and Forsaken by Kelley Armstrong, I don't think either will feature in my Hugo nominations. Jacaranda, though ostensibly set in Priest's steampunk alternate timeline of Hugo-nominated Boneshaker, is really a ghost story about a haunted hotel, and Forsaken (which I didn't finish) is urban fantasy about international werewolves in today's world; neither ticks my subgenre boxes (though Jacaranda is well spooky).
Strange Horizons also surprised me with the heavy proportion of fantasy to sf in its Jan-Mar output. A lot of it is good, of course, but I lean a little to the sf side in general and especially when considering the Hugos. The SH story I liked most, Amal El-Mohtar's "The Truth About Owls", is ineligible because of prior publication in 2014. The other story that really grabbed me with an emotional gut punch was the very first one of the year, L.S. Johnson's "Vacui Magia". I think it will be on my list in the Best Short Story category (at a little under 3500 words), though as will become clear my nominations in that category are already getting a bit crowded.
Tor.com also has a digestible number of good stories. I see a lot of love out there for David D. Levine's "Damage", which I don't really share; it's a neat enough story about a sentient warship, but didn't seem to me to push the envelope much. I guess the point is that the Puppies claim to like that kind of thing. My own favourite from Tor.com, which will definitely be on my nominations list, is Nino Ciprio's "The Shape of My Name" - time-travel romance, perhaps, but with a very new twist to that venerable trope. At 6500 words it too falls into the Short Story category.
It took me longer than it should have done to realise that only about half the stories in this year's Clarkesworld will be eligible for next year's Hugos, the rest being reprints. From issues 100-102 covering the first three months of 2015, Naomi Kritzer's "Cat Pictures Please" is getting a lot of positive reaction. Myself I thought it was a one-joke story, and I prefer the Hugos to go to more serious stuff, but I suspect it will tick a lot of people's boxes. Another story that I think is objectively good but didn't excite me was "Ether" by Zhang Ran, translated by Carmen Yiling Yan and Ken Liu. The Clarkesworld story that really grabbed me hard, despite its graphic violence, was Kelly Robson's "The Three Resurrections of Jessica Churchill", at 5300 words yet another for the Best Short Story category.
The only traditional magazine in my initial roundup is Asimov's; I know that F&SF and Analog and Amazing continue to produce good stuff, but for now I am establishing a baseline from a magazine that published three of my personal picks in the last five years. Asimov's publishes solid sf, often not terribly exciting and a little old-fashioned, but catering to an important part of the audience. Each of the three issues I read (January, February and March 2015) had a story that I reckoned was worth nominating for its traditional virtues. For January 2015 (but is it eligible, having been on the shelves the previous month?) it is Allen M. Steele's "The Long Wait," apparently the conclusion to a series of stories about a generation starship (drawing from the same well as his Coyote stories, which I also liked) and those monitoring its progress on Earth; I only found this out when writing this summary, and certainly found it perfectly accessible even though I had not read the previous parts of the series. It's marketed as a novella; I haven't counted the words but that seems right to me.
For February 2015 (again, I worry that this hit the shelves in late December) the standout story for me was a novelette, Eneasz Brodski's "Red Legacy", apparently the author's first professional sale, which throws together cloning, an alternate Cold War, Lamarckian genetics, Soviet heroes and fiendish Brits and Americans, and some moments of impressive horror. The issue also included Michael Bishop's "Rattlesnakes and Men", which I found a rather heavy-handed satire of American gun culture, but no doubt readers who are closer to that situation will get more out of it than I did.
The March 2015 issue ends with Kristine Kathryn Rusch's novella "Inhuman Garbage", an excellent detective story set on the Moon (and thus turned out to be good mental preparation for Ian McDonald's Luna: New Moon, of which more in due course). Apparently it too is part of a series, but I had no problem with getting into it. A dishonorable typographical mention, I'm afraid, for "Pareidolia" by Kathleen Bartholomew and her sister, the late Kage Baker, in which Byzantine-era Greeks address the narrator as "Kupios" in the Latin alphabet. First, the Greek word is properly spelt "Κύριος" which transliterates as "Kyrios". Second, if you're using it to address someone it should be "Κύριε", as in "Kyrie eleison", "Lord have mercy".
Score so far of potential Hugo nominees:
Allen M. Steele, "The Long Wait" (Asimov's, Jan 2015)
Kristine Kathryn Rusch "Inhuman Garbage" (Asimov's, Mar 2015)
Lois McMaster Bujold, Penric's Demon (Spectrum)
Eneasz Brodski, "Red Legacy" (Asimov's, Feb 2015)
L.S. Johnson, "Vacui Magia" (Strange Horizons, Jan 2015)
Kelly Robson, "The Three Resurrections of Jessica Churchill" (Clarkesworld, Feb 2015)
Nino Ciprio, "The Shape of My Name" (Tor.com, Mar 2015)
And on to the second quarter, April, May and June.