Step 1: Choosing Your Guitar
Since you're starting out, probably the guitar you have in mind is the one your favorite guitar player owns; That guitar's usually pretty expensive and well...it's expensive! So aiming for a budget guitar is a good thing to do, because depending on your commitment to guitar, who knows you might quit playing from the first week or you might keep on doing it forever.
There are a lot of knock-off guitars that are available at very decent prices, and you don't have to buy the first one you lay your eyes on, shop around and try to get the best deal out of it.
Guitar shapes are endless, try to pick the most comfortable for you, I'd suggest Les Paul or Stratocaster shaped guitars, they are very comfortable and since at first you're mostly gonna play whilst sitting down, you don't want something like a V shaped guitar, it's not that comfortable unless you're standing up.
A lot off well known guitar companies make a starters package for beginners; they include a guitar, an amp, cables, a strap and a tuner so this could be a really cool thing to buy!
Step 2: Your Strings
Preferably start out with a light gauge set of strings (a set of 9's for example) till your fingers develop calluses and work your way into sets of 10's or 11's depending on the music you're playing, whether you're gonna be down tuning your guitar and stuff like that.
String Maintenance is also important, you should change your strings when they don't stay in tune anymore or if they don't sound as good anymore.
You should always clean your strings after you play, wipe off the strings with a cloth to get rid of the sweat and all the crap that gets stuck em, and they'll definitely last for a longer period.
Step 3: GET A TUNER!
This is crucial for any guitar player especially for beginners. Your guitar should always be in tune if you wanna develop a good ear and to be able to hear the right sound when you hit a certain note.
Step 4: Your Pick
If you're into rock/metal music, start off with a heavy gauge pick like the Fender Heavy, this is the most fitting pick for that purpose. You can experiment till you find what you like best.
Step 5: Your Amp
Practicing at home doesn't need more than a 15W practice amp, there are many types; some of which have gain built in them, others have other effects like reverb, delay and chorus. Get the one you like and don't go for huge combo amps or anything of that sort because it's just too early for that.
Step 6: Your Effects
You'll find yourself wanting to add some color to your sound, you have an endless variety of stomp boxes to choose from, shop around and get what you like.
The other alternative for stomp boxes is multi effects units, which are basically a collection of stomp boxes jammed up into one unit. They're not as easy in their interface as stomp boxes, but they'll save you a lot of money instead of buying like 10 different boxes one for each effect.
-Guitar String Brands that I use and recommend: Ernie Ball and D'Addario
-Guitar string/fretboard cleaner: GHS Fast Fret
-Guitar Straps: Levy's Straps
-Guitar Picks: Dunlop Gator Grips: Your pick will never slip from your hand...EVER!