I'm not too sure about including a craft guide in default. For beginners a craft guide might be essential, so they don't end up being frustrated. More "pro" gamers won't need it (most times, only for convenience) so either it should be optional or quite unobtrusive. Anyway it shouldn't be some "monstermod" like unified_inventory since it does too much for my taste.
In singleplayer I go with craft_guide, by cornernote :). I chose it because it is seperated from the inventory. You craft the guide and put it somewhere. Since minetest_game comes with give_initial_stuff I can imagine this would work quite well on servers. Big pro here: It doesn't make things too easy. You have to place the guide somewhere to have a look at it, so either you have to go to a craft guide or carry one around or craft one more and since there's no "copy to grid"-option beginners will still learn recipes by and by. Counter example unified_inventory: I made some mahogany nightstands (homedecor) yesterday and can't remember how since I copied the recipe to craft-grid over and over :D.
Anyway, since the choice of craft guide strongly depends on personal preferences a temporary improvement would be to include and introduce more of them in the
wiki FAQ (atm it only links to Zeg9's craft guide).