The hardest part of your journey won't be your final set of an intense workout or keeping up with your diet, but simply showing the necessary patience and discipline. Going from skinny to buff takes time. There'll be days when it seems easier to skip the routine. It's in those moments that you have to buckle down.
It'll help to take small steps. Rather than focus on gaining 20 pounds (9 kilograms) of muscle, go for 5 pounds (2 kilograms) at a time. You'll reach your goal faster and be more motivated to stick with the plan. Commend yourself for the things you've done rather than all that you have left to finish. It's all about perspective.
Finally, have fun with it and know you're not only getting buff but you're laying the foundation for a lifestyle that'll keep you healthy for years to come.