There is a close reason on Stack Overflow that says,
Questions asking us to recommend or find a book, tool, software library, tutorial or other off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam.
However, we have already decided that book recommendations are on-topic as long as they are not too broad and there are a number of questions asking for online resources as well.
- Is there a backpacker's guide to edible plants that is very light?
- Near-realtime satellite snow-cover imagery via easy web-interface
- Where can you find an online elevation profile of Tahoe Rim Trail?
- Good resources for information about hiking trails near Boston
- Interactive online map of long-distance / marked trails against best freely available topographic map background
- Where can I find the current status regarding fire bans in Norway?
- What are some good guides to the U.S. national forests, specifically those in California?
- Where do you get GPS tracks (hikes) for southeast Asia?
- New Zealand recommended hiking maps, books and other resources
- Is there a website with current river water levels for Arizona/Utah?
- Is there an equivalent of "The A.T. Guide" for the Pacific Crest Trail?
- Is there a tool that can calculate the time of sunrise?
On the other hand there are at least two that are closed for this reason
- Is there an interactive map of skiing resorts with snow forecasts?
- Online instructional videos for crack climbing
Why are just those two question closed? There are other questions asking for online maps and resources and it seems like the community has found them useful.
There are always questions that we will need to point people off site for the answer, (there was one where the answer was to call someone) but I don't see as how that means we should close them.