help with wooden worktop maintenance please!

[ohmygoshandgolly]

Can anyone give me a step-by-step guide to sanding and revarnishing my wooden worktops in the kitchen?

I have been putting off doing it because I am terrified of ruining them!

I know I need to sand them first but what grade sandpaper do I use? There are marks that need to be 'sanded out' but how do I do this without damaging the whole worktop?

Which varnish should I use? How do I apply it and how many coats? They are oak.

I am clueless so speak to me like a 4 year old please.

Thanks

Thank you so much, this is really helpful.

Do you just do one coat of oil each time? Or is it worth doing a couple of coats for extra protection?

can you link to some sites which sell oil? or does b&q stock it?

Alternatively, Danish Oil from B&Q.

Oooo we moved into our house with wooden work tops in may and have not done anything to them yet! I need to oil them????? So you jus rub Vege oil in? I'm so clueless