Before learning to conjugate Spanish verbs, you should learn the fundamentals.
Understanding the basics is far more important than learning to conjugate 501 Verbs in 30 days, or whatever.
Undertanding the basics will help you learn to conjugate regular verbs in Spanish almost instinctively.
That will only leave you with the issue of irregular verbs... and that's already half the battle won!
Understanding the basics consists of understanding a few Grammar rules, but don't worry. It is not as difficult as people believe it to be.
Many of these grammatical principles also apply to other languages such as English, and they are not too difficult to grasp.
Basic Rules for Verbs in Spanish
A verb is a word for an "action, passion or status". For instance, "to kick" is an action word, "to love" is a passion word (feelings word), and "to be" is a status (or being) word.
Conjugating a verb means to recite it for different subjects ("I", "you", "he", "she"it", "we", "you", "they") and in different tenses ("past", "present", "future", etc). For instance, you conjugate the present tense of the verb "to read" as "I read, you read, he/she/it reads, we read, you read, they read".
In Spanish, verbs have 2 parts: a stem and an ending (or "suffix").
The infinitive of a verb is when the verb is "neutral", so to speak. That is, when the verb is not doing anything because there is nobody using it. For instance, when you say "to write" (escribir), the verb is doing nothing (or rather, nobody is writing. Get it?).
The infinitive also translates into English as a verb ending in -ing (or "gerund"). For instance, "lo sabe sin estudiar" means "he knows it without studying"in English.
Verbs in infinitive end in "Ar", "Er" or "Ir". Check the Spanish pronunciation section of this site if you don't know how to say them (at least, till I get my audio files set up!). For instance "Amar" (to love), "comer" (to eat), and "vivir" (to live).
You conjugate regular verbs by changing their endings for the appropriate person or subject, and in the appropriate tense
That's it. That's the basics of Spanish verbs. You don't even have to learn it by heart. You can always come back to this page for future reference.
Of course, there are many other things to learn in relation to verbs, but the above points are the most basic ones. You will learn the rest as you go.