To give you a (probably not quite so by the time I've finished writing) quick run down.
So you're in theatre! Hello! The anaesthetic nurse (and anyone else in the room) will greet you. They'll get you to sit on the edge of the bed and confirm your identity. You'll be asked this multiple times in the day. We're not trying to steal your information (though anyone asking your mum's maiden name might be...) but positive patient identification is extremely important, and while everyone might be there for the same operation, it's vital to have the correct patient we're expecting.
If you haven't had one put in already, next up is the cannula. Definitely have the EMLA cream. Squish your husband's hand, close your eyes, and keep breathing. It'll be over before you know it. Much like the spinal and the C-section itself! After that is some monitoring being attached (BP, finger oximeter, ECG), your back exposed, pants removed, and it's spinal time.
Your anaesthetist would have gone off at some point to go and get scrubbed, and will be getting all the paraphernalia they need ready. It's all behind you, so keep looking at your husband, chatting with everyone in the room, sing along to any music playing in the theatre (if I get my way it's Christmas music, but you're the patient, so you get to choose!).
Spinal itself. First up you've got to have your back sterilised. In my trust we spray you with a sterilising solution. IT. IS. COLD. Do not listen to anyone who tries to tell you it's 'refreshing' or 'cool'. No it isn't. Freezing is the word. Alternatively you might have the same solution painted on. Same deal.
Once it's dried (doesn't take long) a sterile drape is stuck to your back, and the anaesthetist will feel your hips and the bones in your back to find the perfect spot for the spinal. "The Position" is then assumed. Hug your pillow, chin to chest, drop your shoulders, and stick your lower back out like the angriest cat that ever catted (or prawn that ever prawned I guess). Some local anaesthetic is injected. It stings a bit, but rapidly goes numb. Steady breathing, try to stay relaxed, test how well your husband's hands withstand crushing forces, sing your favourite song. Hypnobirthing affirmations might help too.
Now it's the spinal needle. As Greybeardy says, it's actually a very thin needle, just slightly long. Nothing huge about it at all. But thanks to the local, nothing should feel sharp or painful. You might feel some pressure, but if it's painful, let the anaesthetist know and they can inject more local. Once the space is found the good drugs are injected, needle removed, we get you to lay down, and all done!
You might feel a warm sensation going down your bum and legs when the drugs are injected. You may find you start to get some tingly pins and needles feeling not long after.
Hope my essay helps a little.
Best of luck on Thursday!