The basic translations of いく and くる respectively are "to go" and "to come". In English, it's really the same implicit meaning, but we just don't use it that way. But for Japanese, think of it this way:
Friend: "Won't you come over?" (meaning to where your friend is now - his house)
You: "Sure, I'll go over." (meaning to your friend's house)
Japanese:
Friend: "きませんか?"
You: "ええ、いきます。"
It's really quite simple: if you're moving away from your current position (or if someone is moving away form your current position) - they are GOING (いく) away from you. If someone is moving towards your current position, they are COMING (くる) towards you. Just remember that the english, "Sure, I'll come over." doesn't translate into くる because you're not moving towards yourself - you're moving away from where you are towards your friend (so from your friends perspective, you are くる-ing).
As far as も is concerned, I assume you're talking about も after ~て? If I use the sentence (I'll only use hiragana, not knowing your kanji ability): それをいってもだめです。 (Even if you say that, it's no good.) The も implies an "even if" situation. Xて・でもY (where て・で depends on the verb) means "Even if X, Y." I hope that helps a bit.
Something to consider is でも at the beginning of sentences - typically translated as "but." However, the linguistic origin suggests that it's a contrastive-も and a shortened form of それでも - Even if that... (or to include the verb, "Even that being..."), which means "but". ^_^