I am a semi-beginner, but it would be helpful to the group if you don't limit your answers to just "beginner problems". If I'm lucky, this thread will serve as a resource for many. I can do a lot of legwork (probably slowly, but I'm game).
In this thread, I'm only interested in online resources or apps. I have a few problem books, and use them sometimes, but a computer-assisted list of problems is easier to follow, and offers some conveniences over a problem book. Even a cursory search yields a few obvious resources, but none of these are what I'd call excellent. Perhaps we can make them so. I'll give an example of a site that I consider excellent at the end. I assume there are more out there.
1.
Sensei's "Go On The Internet" page. This is good (I haven't followed all the links yet), but, inevitably out of date, with broken links and other issues. With enough help in this thread, I can maybe update that page, so that it becomes the go-to resource for everyone.
2. Threads on here, like
this one. I've done a bit of searching here, and can do more. Again, there is valuable info, but it needs investigation and collation. I'll try to do more collation of that kind of information over the upcoming weeks.
3. Phone apps. I'm aware that many Go resources have moved to phones and tablets as apps. Again, it's all good, and I'm not opposed to paying for quality in that realm (free is also good

). But having some advice from those who have used those apps, nicely compiled all in one place, would be ideal. If you recommend something, please give us a few words about what is good and bad. Again, I can facilitate creating a list of apps, but will need help from others on the contents. I don't have nearly enough time to try them all.
4. SGF's. If there are places to get problems as SGF's, either paid or for free, let us know.
5. Anything I've missed?
Now, to illustrate what I think is a good example, I recently stumbled on a bunch of life/death problems on the WBaduk (previous, CyberOro) site. For those who haven't heard of it, this is a large (free) Korean go server site for China, Japan, and Korea (along with ROW). Here's how to get to the problems (which are mostly life and death, I think):
1. Go to the
WBaduk site and download the app. Java required.
2. Start the app and log in (free account required).
3. You'll see an icon labeled "Problem" on the right-hand side, but you can't get there without logging on to a specific server. To log onto a server, click on the Server link at the top right, double-click on one of the 7 servers and login in again with your account. The list of active games on that server will appear. if you don't feel like getting invited to games, click on "Setting" at the top, go to the Invitation tab, select "Ignore all invitations" and OK out.
4. Now click on the Problem icon on the right, and you'll get to the problems. There is one dropdown for difficulty, and another that lets you choose to see all problems, or only the ones that you haven't already solved. The ability to come back later and pick up right where you stopped is a big convenience.
These problems are nicely implemented and, while they don't have any real explanations, it's easy to get started and blast through a bunch of problems. As mentioned, the site remembers where you left off for next time. It's a major resource for a beginner (and hopefully for more advanced players too). If there were more sites like this one, we'd be very lucky. Here's a list of sections and counts of problems.
1. Beginner (25K - 20K) -- 156 problems
2. Easy (19K - 15K) -- 365 problems
3. Easy (14K - 10K) -- 1161 problems
4. Middle (9K - 6K) -- 398 problems
5. Middle (5K - 2K) -- 264 problems
6. High (1K - 2D) -- 193 problems
7. Expert (3D - 7D) -- 114 problems
As you can see, this is pretty generous, for a free site. Please check it out, if you've never been there.
I won't rattle on all night... please contribute links and app recommendations, and give us a few hints about what's included, and the level of expertise that would be required. I'm hoping we can keep this thread going for quite a while, and turn it into a compendium of resources for online problems, etc.
Thank you all for any assistance you can render. Let's make this a valuable thread.
-- Gohst