How do I tape and paste the drywall seams & screw?

Not too difficult but it is something that takes some practice to get right. Read up on it here:

Taping Drywall Step by Step Instructions - How To Tape Drywall

The only thing that site is missing is a big time saver like doing the first coat with 45 minute compound. The redi-mix stuff in the 5 gal. bucket can take more than a day to fully dry. The 45 minute stuff is rock hard in 45 minutes. There is a 20 minute compound but even I can do much in 20 minutes.