Hi Denise,
I have done a couple of 5k races too - and have got a 10k race tomorrow! (arghgh) I started running in april, so I think I have done quite well.
It wasn't too bad building up to 10k, but I have to admit I am not the best at keeping up with training (miss the odd session). However, I have done several 6 mile training runs, and it is quite enjoyable. I will have sections tomorrow that I might have to walk - but I am not here for record times, I am merely wanting to improve my health, strength, stamina and to enjoy myself, (it is such a buzz when you complete something like this).
There is a great beginners 8 week plan for a 10k race. It will be here somewhere - try the section called training.
Go for it - if I can do it anyone can (my idea of fitness was running for a bus not so long ago - and I couldn't even do that!!)
best wishes
go-slow