Firstly make sure you have a good sleeping routine, working from home can be tricky and you can loose track of time very fast. Get up the same time of the morning, have breakfast, a shower and clean clothes.
I usually start my work day with a coffee and news.com.au for the first 15 minutes, then I check my emails etc and reply to the urgent stuff, then I start my day.
I have a dedicated hour break, leave and go for a walk if you have time, eat some lunch, surf the net and waste some time.
Another coffee and back to work.
I think the hardest thing about working from home is DISTRACTIONS, there are so many, and when you are your only boss its really easy to get distracted with something and before you know it 4 hours has gone.
good luck!