For both the projects I'm working on, I write, illustrate and finalize everything myself, but I have it proof read by my girlfriend :U For the most part, it's just me and it's very tiring and time consuming, especially when your tablet breaks ^^"
Researching professional comics online, at a certain point (which I am considering on doing soon), it is a good idea to hire an inker, a color blocker and a proof reader in order to aid with the production as well as to speed up the process 