Learn to speak Spanish, if you don't already, as the majority Mexican telenovelas are aired only in Spanish. While speaking the language helps, the characters and scenes are generally so over dramatic, that it should be easy to get the gist of the plot whether you speak the language or not.
Find a Mexican telenovela that is offered with English subtitles or a DVD that is actually dubbed in English if you find it easier to follow along that way.
Watch the first episode of a Mexican telenovela and you will find following the entire series much easier. Often during the first few minutes of the very first episode, you can determine what will happen in the end; the couple that is kissing each other will encounter some sort of struggle, but will kiss again in the final episode.
Determine the genre of your favorite Mexican telenovela, to help you follow the plot. The classic "working class melodrama" will most likely feature a poor girl in love with a rich boy, whose family rejects her. A teen drama will center on a high school and will be focused on the struggle against the temptations of sex and drugs. The pop music genre will be similar to the teen drama, only it will center on the lives of aspiring popstars and their day-to-day struggles.
Tune in for as many episodes as possible. Mexican telenovelas are not structured like American soap operas, running day after day, for years on end. Instead, they usually include an average of 120 episodes, running between three and six months, and then they end. Missing an episode can prevent you from understanding the rest of the series, without any hope of catching up.
Know your characters to better follow the plot of your favorite Mexican telenovela. Keeping each character and their motivations straight will help you follow the development of the plotlines much more easily.