Jo, I'm glad you like it so much. I used 4-ply wool and a 4mm hook for this pattern, but for a beginner get some double-knitting wool (sometimes also labelled at DK) and a 5mm hook.
Do a chain as long as the blanket should be wide, make sure your chain isn't too tight as you will need to get the hook through each loop in a minute.
The first "proper" row is the hard bit, just battle through this. Get ready to treble - that's put the wool on the hook, go through the space you're supposed to be trebling into, get the wool on the hook again and come back through the hole so you have three loops of wool on your hook. Now hook some wool and go through the first two loops (you should have two loops left now), and hook some more wool and go through the last two.
Still with me?
Now you know what to do and we're ready to start. Treble into the 4th loop from the end of the chain your hook is attached to. Treble again into the next stitch back along the chain (crochet works right-to-left so get the end of the wool and the first bit of the chain to your left, then you and your hook should be at the other end coming back along the chain to the end you started chaining from).
OK. Do a single chain stich. Missing out one of the loops in your original chain, treble into the next three of those loops. Just keep going with a single chain, and then three trebles in a row until you get back to where you started.
You've finished the first row. Let me know if you make it and I'll post the rest of the instructions (it gets much easier from here I promise, I'm just finding it hard to type all this into such a small box!). If you need photos I can send some :)