Hiya op.
I have been doing this for absolutely years, probably about 10....Im not sure if I notice a difference any more, but its part of my daily routine now, and when I go a few days without, not very often, I do notice the difference.
As pp have pointed out, if this is a long term change for you - you MUST drink out of a straw, as it will ruin your teeth.
I have several stainless steel straws for this and is perfect, although they do get hot to begin with so you might need to wait for the water to cool.
Always start with a few fingers of cold water in the bottom of the cup, so the boiling water doesn't totally destroy the vitamins in the lemon.
I do 1/4 slices and squeeze as much as i can out and leave the rind floating.
Organic lemons are best as no nasty pesticides on the peel, but i must admit I'm not that fussy, but i do buy organic when I can.
Another thing I discovered after a few years was turmeric, few shakes of turmeric, which has huge and far reaching health benefits in your lemon water is delicious and gives it another little edge. I remember thinking it was going to be horrible when I first tried it, but its great -and even if you're not keen at first, stick with it.
My DS (6) also has lemon and turmeric water in the morning, but i put a 1/4 spoon of manuka honey in his to make it more palatable.
This may be good for you too, although I personally stopped because of calories.
Wishing you many happy lemon water years 