Not the only truth out there but if the answers of a nobody can help you 
. after several test, I will be sticking with 800 pixel wide picture so that the picture aren't too agressivly big when you watch it on a computer (it till is a bit but I think that's the right size) and are perfectly readable on a phone
. I think updating regularly is more important than updating lots of page in one go, I dedicate the week end to my webcomic and whatever gets done is posted
. For a font, you can search for free one on the web, I use Architect Daughter, I find it elegant plus it allows french writing (since I do my comic both in English and French, it's cool for me), all that to say, if you plan to do stuffs like é, è, ç and all, I fint it a good choice (if you want to check, here is how it looks like on my comic )
. I guess the tips are the same that if you want to draw or do "real" comics : persevere, accept criticism (the argumented one), a good story is better than a good art and when you read comics, stop just being a reader and try to understand why it works (you can do it while watching movies too)