Wildwinds the online attribution site.
Contains a huge database with great search engine capabilities (by emperor or partial inscription among others).
Doug Smith's coin
view and Doug Smiths Ancient
Greek & Roman coins
Two absolutely wonderful sites with tons of great articles for beginners by
Doug Smith a private collector exploding with knowledge and the willingness
to share it 
.
De Imperatoribus Romanis
An Online Encyclopedia of Roman Emperors a huge site with information on all
the emperors a coin archive and the Imperial Battle Index.
Studying and Collecting
the Coins of Rome and her Cities.
Another brilliant site for beginners with tons of info and articles well worth
a look.
The Illustrated History of The Roman
Empire.
A site of 70 megabytes of info on the Roman Empire, great site with info on
literally everything.
Forum Ancient Coins.
Holds a huge coin catalogue with search capability, several articles and a
great Discussion Board with lots of helpful people.
Virtual
Catalog of Roman Coins.
Another searchable database this one is aimed at students and teachers and
has lots of info on Roman coins.
Ancient Impressions Attribution.
A great resource site for beginners with tons of info on abbreviations, roman
mints, coin terms, emperors and much more.
Ancient Roman And Greek coins,
FAQ.
Another great site for beginners with lots of articles and tips.
Dave's Ancient
Coin Page
A collectors personal coin page with nice tips and a quick history of all
the emperors called "Those Wacky Emperors".
Joviels site on uncleaned
coins.
A site of an avid collector of uncleaned coins with tons of before and after
pictures plus info on where he bought the coins and whether or not the lot
was any good.
Anatomy
of a Roman Coin
A great article about the story on a roman coin and how you can read the story
from the coin.
Beastcoins.com
A site from a collector who shows his different type of collections with among
others, surprise surprise
,
a collection of roman coins with beasts on them.
Dirtyoldcoins.com
A website from a seller of roman coins with tips on how to clean and attribute
coins and a database with pictures of coins by emperor.
Rome and Romania 27 BC - 1453
AD
A very complete site with the history of the Roman empire till well beyond
the date of the roman coins on my site.
Coins of Roman Egypt
A great looking site about Roman coins minted in Egypt with lots of pictures.
cgb.fr Numismatics
A site of a French coin dealer with tons of pictures of roman coins with descriptions.
(The descriptions are in French but can easily be translated with worldlingo
or similar online translators.)
Imperium Romanum
A German site with tons upon tons of info on the Roman empire, however the
site is completely written in German so that might pose a problem for some.
Great site none the less.
