For stinging nettles, dandelions & other perenial weeds you should use a systemic weed killer that takes it down into the roots & kills them for good..
I like to spray this on a hot dry day then the weeds absorb it quicker.
Digging or rotavating these types of weed will only make it worse so where ever possible dig all the roots up as even one little bit of root left in they will come again.
Annual weeds can be howed before they set seed.
Not sure if if ok to mention but try an inexpensive book called The Pest & Weed Expert by Dr D. G Hessayon.