purchasing a cellphone in Italy

If it is an unlocked cellphone, you should be able to buy a SIM card for 15 euro or so with 10 minutes already on it and reloadable either from the phone or the internet.

As Sam said, if the phone you purchased in Scotland is unlocked (not locked to a certain carrier), then that will work in Italy. You will need to buy a SIM card. I used the TIM provider, but there are a few other options in Italy too. There is a TIM store in Terminal 1 Area B of Fiumicino - but if you are not arriving in T1 you may not be able to buy it there. There is also one at Roma Termini and other stores all over Rome. Buy a 10€ SIM card (or that was the price in 2011) and you get 5€ of calling credit.

Sam mentioned you can reload minutes online. In my experience, you need a codice fiscale to reload minutes online in Italy but it is easy to walk into any TIM store or to a Tabacchi and purchase minutes to add to your account.

If you purchased your phone in Scotland it should work. Scotland also uses the same GSM standard as the rest of the EU. Your Scottish phone should be unlocked already (I have never experienced otherwise in Europe). Therefore all you need is to go to a cell phone store (yes there is one at the airport and at the station, your choice) and purchase a SIM card. I don't know if the phone you have is a smart phone, but if so, you can get a data plan too. If it's a dumb phone, you'll use it for calls and SMS messages only.
Also the charger to your Scottish phone probably has a 3 prong UK plug, which is different to the 2 round prong plug used in continental Europe. You can buy an adapter at your local Radio Shack or similar store. The socket in Italy, as the rest of continental Europe, requires the Europlug type C (2 in-line round prongs).

I will yield to the knowledgeable people who say your Scottish cell phone will work, but you did ask for experience: I bought a dumb phone from a TIM store 3 years ago, I still use it. I just go to a TIM store to buy more minutes once the phone is charged - you can find a TIM store (there are other brands as well), buy a phone that comes with minutes (mine cost about 30 Euro 3 years ago), load up at any kiosk or tobacco shop that has a TIM sign. When you buy the phone, ask the salesperson to set the time and date functions and to set the language default to English.

Thanks for all the info so far. I do not speak Italian, how much of a problem will that be in trying to make this transaction? Thanks for the tip to ask them to set the time, day and language.

" I do not speak Italian, how much of a problem will that be in trying to make this transaction? "

In general, any store with items such as these has at least one English speaking staff person. No problem since the phone in your hand will prompt them to address your needs.

I would think at the airport and at Termini they will likely speak English since plenty of tourists go through there. Other smaller stores may not have as many English-speakers.