Voici enfin présentés :
past participle, without auxiliary BE which here would be "sont", so it has to agree, masculin plural, "présenter" being a regular "er" verb so past participle ends in "é" plus the "s". Used a bit like an adjective...
sur un pied d'égalité :
on an equal footing
le français dit standard :
the French (language, obviously given the context and the fact that the "f" is lower case, the use of the upper case in French here would indicate that it meant "Frenchman"
et les mots et les expressions du français tel qu'on parle sur les cinq continents.
and the words and expressions of French such as [it] is spoken on the five continents.
The subject of this sentence is two-fold, namely the "français dit standard" and the "mots et expressions", hence the masculine pluiral form, "présentés". French uses a lot more commas than English. If you put commas in as below, then it wil start to make sense. Modern French does rather like short clauses and sub-clauses, all put in a bag, shaken (not stirred) and then put back down onto paper with lots of commas!
Try reading it out aloud, pausing where I have stuck a hyphen in and it will probably come clear :
Voici enfin présentés - sur un pied d'égalité - le français dit standard - et les mots et expressions du français tel qu'on parle sur les cinq continents.
A translation of that might read :
Here at last, on an equal footing, what is referred to as standard French is presented alongside the words and expressions as they are spoken on the five continents.
I am afraid that I can only "do" British English. Blame my parents, they are Scottish. Others may have an American eye and ear tuned in to give you an American version.
First of all, there seems to be a mistake in the French sentence. "le francais tel qu'on parle sur les cinq continents" should really read "le francais tel qu'on LE parle sur les cinq continents" or "le francais tel que parlé sur les cinq continents".
I would have written the French sentence this way:
"Voici enfin, présentés sur un pied d'égalité, le français dit standard ainsi que les mots et expressions du français tel qu'on le parle sur les cinq continents."
I have some kind of feeling that what is throwing you in this sentence might be the use of "dit" in "le francais dit standard". Dit is the past participle of the verb "dire", and "le francais dit standard" is the equivalent of "le francais appelé standard", "French which is called standard".
Also, "présentés" is plural because it refers to both "français standard" and "mots" and "expressions". All three are presented in this dictionary.
If I translate the sentence more or less word for word, you might be able to understand its structure better. Here it is:
"Here at last, presented on an equal footing, are what is called "standard French", plus the words and expressions from the French language as it is spoken on all five continents." Does that help you understand the grammar of the French version better?
Since this is an introduction found on the cover of a dictionary, and therefore is meant to attract people's attention, I would suggest a translation of the sort:
"Here it is at last: A dictionary that presents "standard French" together with all those French words and expressions from every country in the world where French is spoken. " or "(...) all the French words and expressions found ( or spoken) throughout the world." or "all the French words and expressions you may find (are likely to hear) anywhere on the planet."
Does this help?