You will need the following
This is completely up to you because each guitar sounds and feels differently. Also weight differs. Remember, You dont need the most expensive guitar. You need to feel comfortable with your guitar, like the sound, and dont fall into dept (no really dont go for highest price Im serious).
I use a Korg chromatic tuner CA-30. I tried others and had bad experiences so thats all I can say.
The strings are completely up to you however I recommend not getting light since its the first time playing guitar and dont yet know you dont ever pluck the strings also even if you dont pluck the strings light strings are for playing higher notes (solos and shredding and whatnot) so getting them as a beginner is a no. Also do not get them too tick. Those are for metal or simple to say for playing nothing but chords, and seem quite abusive if you ask me, but I play metal with an effect pedal so I dont need to feel it crunchy it just sounds that way. I recommend getting them all at once. Get a .8 or .9 on the thinnest string. The higher the number the ticker it is.
If you dont have one dont worry but depending on what you want to play you may need to pick one up. I recommend light picks because there most flexible, but first time through you should get a medium. You may yourself feel most comfortable with a medium. Remember, you dont force your right hand.
Now you have your guitar or acoustic guitar and, your strings, and tuner; hopefully
Lets say you need to put on the strings:
for an acoustic guitar usually people get the strings separately. Well what ever the case, the pins at the bottom are lifted (gently pulled out) and the ends of the string (the ones with a bud) go in there. Now close them up with the string in side them. Put the other end of the strings in the holes of the tuning keys (on the opposite side of the guitar) leaving a little extra string out for the turning process. Turn the tuning key for the current string. I start with the tick strings first and move up. Dont try tuning them yet just get them on (not tightly; remember, they can pop).
in the back of electric guitar there are some holes to slip the thin end of the strings throw (the ones without a bud). Then they come out the other end respectively and you put them in there respective tuning keys leaving some space to turn them. Post Note: do them one by one trust me (thickest to thinnest).
they go in pretty much by tying them to the bottom and putting the thin ends (the ones without a bud) in the tuning keys; just roll them like I said for the acoustic.
EADGBE (Thickest to thinnest)
for now all you need to know is that the notes go ABCDEFG. Notes only go by these letters. And yes, there are more then 7 notes. This letters repeat themselves as so, ABCDEFGABCDEFG. All it is is A to G followed by A to G. It continues forever, or at least to were the human ear can hear but that is going into detail. Here are the steps:
Tune from the thickest string to the Thinnest
The first is an E. Since you shouldnt have them tight right now, they are loose and need tightening. The tuner should be on. If you are working with an acoustic guitar then put the tuner near you by the hole if possible. If you are working with an electric guitar plug in your tuner to your guitar with a chord or put the tuner near (near enough) the amp (only do this if the tuner cant plug in with the chord otherwise please use the chord). Okay now we tune tighten it a little till we see the note change upward, A-B,D-G,G-A, and so on. When it gets to an E you try to get it to land in the middle. It doesnt have to be too exact right now you going to have to tune twice to get use to it. Thickest to thinnest followed by thickest to thinnest. You will notice how they change balance after tuner the other strings. Well all guitars are different, but a lot of guitar will do this
Hopefully that helped
Next lesson covers starting to play followed by playing (yeah)