There are three types of tequilas, the difference being the amount of time they are aged.
Blanco ("white") is the clear and most people find this style of tequila the strongest. It is bottled or stored immediately after distillation or it is aged for 2 months or less in stainless steel or neutral oak barrels.
Joven ("young") or Oro ("old") refers to the golden tequilas that are often mixtures not containing 100% blue agave- the plant grown and harvested to make tequila.
Reposado ("rested") is a tequila aged anywhere from 2-12 months in oak barrels.
Anejo ("aged" or "vintage") spends anywhere from 1-3 years in small oak barrels.
Extra Anejo is a new category of tequila just added to the list 6-7 years ago, can't remember off the top of my head. There is no maximum aging time for an extra anejo, but it must spend at least 3 years in small oak barrels.
When purchasing tequila, simply look for "100% blue agave" on the label to make sure it is true tequila and not a "mixto" or mixture of some tequila (not less than 51% blue agave) and some other form of sugar or fructose.
The traditional Mexican working man's way of drinking tequila is a small juice-size glass of blanco and an equal size glass of sangrita, a sweet, sour and spicy juice made from chilis, grenadine and oranges (there are several good recipes out there). A sip of blanco tequila followed by a sip of sangrita. This is the traditional, after-work social drink of the Mexican working men when they gather. Somehow, this traditional method of drinking tequila devolved into "training wheels," the lime, salt, shot of tequila practice commonly seen in this country.
In Mexico, Reposado tequila is sometimes referred to as the women's tequila because it is smooth and doesn't have the grain alcohol finish that most Americans find offensive.
Anejos are like drinking fine scotch. They are to be sipped and appreciated for their complex flavors and can be the most expensive tequilas on the shelf.
I don't drink many liquors at all and I've never acquired a taste for any colored liquors. The occasional Tanqueray gin or a vodka drink, but I have one of the finest tequila collections in the state, I would venture to say. I have done private tastings and educational classes on tequila and absolutely enjoy speaking with anyone on the subject. It is an acquired taste and a great hobby- I travel to Mexico every year and make a trip to Tequila, Jalisco to see what the latest is.
I did a tasting at a private country club last year. You know, the typical cigar-smoking, scotch drinkers. By the time I was 10 minutes into it I was surrounded by a bunch of 40-60 something's who were fascinated and hadn't drank tequila since their college days... converted a bunch of folks in one night.
But, back to your maragarita... if you use a blanco tequila, you should add a splash of Grand Marnier which will kill some of the grain alcohol flavor, knock down some of the acid of the lime juice and add some golden color. If you use a Joven or Oro and it's not true tequila, you'll need to splash the top with a Sprite or 7-Up to kill some of the lime juice acid. I'm a tequila connoiseur, not so much a margarita guy.