I just wanted to say don't listen to the naysayers. As you say, these days everybody has a child for selfish reasons, including people in relationships. The world is already overpopulated and it's hardly a 'lie back and think of England scenario' anymore. We all have children because we want them and it surprises me that people in relationships use this as an argument against single motherhood.
As for having no father. There is quite a bit of research on this now, and again and again it all points to the importance of a stable home and consistency being the most important factors in a child's happiness and attainment - far more so than having 2 genetic parents. A single parent is far far better than 2 parents who are constantly arguing, fighting or not talking and "staying together for the kids". And based on the adults I know who went through this when they were kids, that's what causes long term trauma and the need for therapy...
As for tips, my best friend had a child with donor sperm and she's said it's much easier than she ever imagined, she thinks it's because she expected to be doing it all from the start - she hadn't expected to have a partner to help her out, she didn't go through the trauma of having a partner leave her. You can have cornflakes for dinner and go to bed at 7pm if you want, you don't have to keep in-laws happy, you can make your own plans and parent in the way you want (again, parenting style is one of the major causes of arguments in couples with kids).
However, my friend does feel the lack of a support network and if I were you that's what I'd really plan for now. If you don't have good friends locally, you could join the DCN and meet people in the same boat so you can be each other's back up in emergencies? (e.g. if you are ill or have to go to hospital in the middle of the night). This actually happened to my friend and she was offered to have social services take him into temporary care for a couple of days. So it is possible, but absolutely not optimal - imagine a 2 year old with complete strangers for 2 days. (She didn't have to take them up on the offer in the end, as a local friend stepped in).