If you do it for practice or just for fun, so my congratulations. But if you really need something like production ready tilemap editor, you can look at tiled although it isn't user friendly
yup i know about tiled from hubert who posted below. in my game engine i have very specific (weird) limitations:
- map must be 10x10 tiles
- can have only 1 layer
- tiles are stored in an array of arrays
so i made this tool that can only produce maps i can directly paste into the engine. in other words - this is production-ready for me :D