I know nothing about locating microfilm but I have some limited experience with using them. You have a groups of films for a particular town (or towns) and a year...so it would be Nati (Births) Town(s) Name+Year(years). All the births registered in that town on that year would be filmed in order of the date registered (which is not always the same as the actual date the event took place).
Indexes are available either in the front of the film or the end of the film of all the people registered in Alphabetical order. The best thing to do when you first begin using the films is to look at the indexes and see if a name jumps out at you and then scroll to that name..yes it may require going back and forth but it will save time. Sometimes if you don't find what you're looking for you will just have to go page by page.
Heres what the indexes might look like..
http://img459.imageshack.us/img459/5420 ... ia19by.png
and heres what a birth act may look like..sometimes the quality is good..other times the films are water damaged and you take what you can get...always a surprise.
http://img409.imageshack.us/img409/1400 ... ia17fh.png
to translate them you could use a site like this one..
http://www.comunesofitaly.org/Links/RuthNerud.htm
which would give you the basics or you could post here. We have several members that can help..the trick is not the the Act itself..its deciphering the handwriting of the person who wrote it! Sometimes you get lucky and the person filling it out was detail oriented..he included the grandfathers/grandparents name and if they were alive or not..others are less documented.
Now..this is what I found with my limited experience..if you really want to know the ins and outs of researching with microfilm I doubt anyone here can dispute the fact that Trish (member brujaojos) wins it hands down. She volunteers in a FHC and specializes in Italian research..If you want a translation from English to Italian..suanj's got it covered since she grew up and researches in Italy..either way, you have a win win situation here.
Many others have researched not only films but parish records and written in Latin none the less which will be my next step this year..James has researched a whole town..I could go on all night but I think you got the picture. Hope I haven't offended anyone..I think everyone's terrific here and has their own level of expertise or favourite area of research (new thread needed maybe

). If you read through pasts posts you'll be able to figure out quite a bit.
Hope this helps a bit.