Materials

Must Have Basics
1) Pencil
everyone needs a pencil to start off drawing. Most people like to use the #2 or HB pencil. It's standard and it's affordable.

Artist’s pencils are classed based on the lead used. B refers to soft lead and tends to easily smudge while H refers to hard lead. H pencils are less likely to smudge but are more prone to making indents on your paper. These types of pencil are optional and ranges up to 5, meaning the softest/hardest type of lead.

Another option from the common pencil is the clicky pencil which saves you from constant sharpening by just replacing the lead. If you draw a lot, it's best to get a clicky pencil with a cushion. If you can't get one with it already attached, you can buy the grips separately.

For those using regular pencils, you can extend the life of your pencils by using a pencil extender which tends to be metallic and looks like the end of your pencil sans eraser. Just attach and screw it to the end of you pencil and you're good to go.

2) 8.5"x11" Paper
The most cost effective paper to use is regular printer paper. For one ream with 500 papers, it's a deal at about $3-4 each. For that amount or more, you can get only one sketch pad with about 30 pages +/-. If you're really tight on budget, use printer paper but I would recommend you eventually get regular sketch and doodle pads. The paper in them is thicker and can handle erasing more than printer paper. Not to mention, if you like coloring your work with markers and so forth, the paper won't warp and bend.

Sketch and Doodle Pads come in various sizes. Choose a size that will work for you (i.e. handle markers, size is easy to transport, etc):
9"x12"
10"x15"

3) 12" Ruler
Standard ruler. You'll need one if you want to draw things - especially buildings and items with straight edges. It's also useful for setting up perspective lines.

4) Work Space
In order to work properly, you need a place to draw your stuff. It's best to draw on a desk but worse comes to worse; floor space is all you need. Some people specifically buy the artist's desk which slants and may have additional features such as holders and so forth. If you're tight on budget or space, an ordinary computer desk or table will work just as well.

5) Eraser:
You can't draw without an eraser to fix your mistakes. The most common eraser is the pink one (aka Pink Pearl) but the better eraser is the white one. When you use the pink eraser, it tends to leave a pink mark especially if you rub it really hard on the paper. Avoid that by getting the white eraser.

For ease of use, some people use the clicky eraser. Like the clicky pencil, the eraser can be refilled as you use each stick up. Other erasers include the kneaded eraser which is like handling putty or clay. You basically put it over the parts you want to erase and it'll pick it up. To "clean" it, you just need to knead it (i.e. pull it over itself like dough).