Upvote:1
I suggest Vodafone or Wind as operators. Tre has a bad coverage outside big cities, you might ask people in your area about that.
You can buy a "SIM dati" in any mobile phone shop, it's a SIM card only enabled for internet. For example this SIM dati Vodafone offers 15 Gb for 35 euros/month or 7 Gb for 20 euros. Unfortunately I think it's a recurring plan, with minimum duration of 1 or 2 years. (Those info are hard to find for us italians too).
Another way would be to buy a regular "pay-as-you-go" SIM and add an internet plan like "Internet Big" for the Wind "All Inclusive" plan, about 11 euros/month for 3 Gb, you can easily de-activate the SIM once you're leaving the country.
The fastest speed you can get is HDSPA, some areas are covered with 4G network.
You plan to travel along all northern Italy or will you stay in only one place?
Another option would be to go to a mobile phone store (there's plenty of them everywhere) and ask. If you're lucky enough you will find a clerk with a good english, get all the informations you need and buy the best internet plan for your needs. =)
Upvote:2
I suggest you the 3 (H3G) offer. http://www.tre.it/promozioni/internet-mobile/chiavetta-tre-it-42
The USB key will cost you 29 euros plus 5 euros / month for 3GB of data (SuperInternet option). It should be a prepaid plan, so if you stop paying and the credit goes to zero you have nothing more to pay, the "SuperInternet" option will just be disabled.
I have a Nexus 5 with H3G data plan (SuperInternet) and I'm really happy with it. :)
Upvote:2
I'll totally suggest WIND it is cheap, nice customer service plus you can buy cheap phones down there to put the card in. Well...you might think of getting Fastweb as well 'cause skype works better with them the only problem is that they do not have phisical shops where you can walk in. You need to call a special phone and get the card shipped . Or if you want to skip the cellphone option you could use an internet key like these ones here (buy them used).
Anything else just write back
Upvote:3
I think 3 (Tre) is providing good internet in a good price. You are looking for something which is called chiavetta in Italy. Are you aiming to use it for a short period? Because if so in my idea it doesn't worth to pay for the modem if you don't own one. Buy the plan for the mobile phone and share it with the laptop.
EDIT
Well I have some time now and could edit my post to add some more detail;
I have read in your edit that you don't prefer contract. This actually does not work properly in Italy because most of the fair offers are contract-based, and you can rarely find a fair Internet option which does not require a contract.
I have found this option that might suit your needs (which in fact needs a contract, abbonamento in Italian):
http://www.tre.it/tariffe/web-senza-limiti
Some notes about this option:
The discount from 19E to 14E is only given if you purchase an iPad Mini or Samsung Galaxy Tab from them;
After finishing 15 GB/month OR 500 MB/day traffic, you will need to pay 20 cents for each 100 MB extra usage;
If there is not access to 3G network (HSPDA) and it switches to GPRS it will cost 30 cents for each 100 MB usage.