It depends on how motivated you feel. When I code/design sites I allways come across problems and lacks of knwoledge but I use Google to search for solutions. I made few websites (Desgin+Code) and I must say it allways takes longer than expected.
It's ok if it takes 40 hours. Next time it will take 38, 36 and so on. You will becaome better in time cose you will fill the lacks with useful knwoledge
