Did my dayskipper theory with a computer based programme from Chichester Marine, not the cheapest but really good.
Customer service was fantastic, two years after completing the course I up-graded my PC, the original software didn't work on the new PC, I sent just one email and within 24 hours Chichester Marine had posted me new up-graded software free of charge.
I did my day skipper and am now doing the Yachtmaster with them, I rate them very highly, the course is very thorough and pushes me, but I know that I will have learnt it well.
Working at home may be very efficient, but you are going to lose out on a lot of additional knowledge that will be shared amongst the fellow students not to mention the experience of the tutor in a classroom.
I did the Coastal Skipper shore-based course with Chichester, and second the other recommendations for them. I intended originally to do Day Skipper, but decided that it would be too basic for me. See this web page here with a "quiz" to help decide which level course you should start at :
I used a CD for YM theory, but have signed up for an eveing course this winter. FIrst bit last night, and MUCH better than PC based. The interaction between the students and the instructors is very valuable. I'm fortunate that my sailing club does it over winter almost as cheap as software...
Yes classes would be much better, but I had none available within usable distance. Sod's law, the year after I did the CM course, the yacht club ran the course over the winter
I did DS theory with NMCS. I agree with most of the other posts in that you will miss out on the shared experience of night school. However the home based course gives you the flexiblity of time and because there is nobody giving you short cuts you have to be very thorough.