This tutorial is a basic guide to exploration. I myself was flabbergasted when faced with the idea of figuring this out so i started looking through the forums and other websites online got some information and started composing this based on the information i found. If you feel this guide helped you under stand exploration then share the knowledge.
You first need to know the equipment needed and the skills they require. Here is a list of the equipment I loaded up and the skills they require. For now the tutorial will only contain items / equipment nessesary to FIND an exploration site. Not what to do once you get there.... that information is coming at a later date.
Gallente: Helios - Covert Ops ship
Skills: Covert Ops, Gallente Frigate V
Item: Covert Ops Cloaking Device II - Allows you to Warp while cloaked
Skills: Electronics V, Cloaking IV
Item: Scan Probe Launcher I - Allows for launching of scan probes.
Skills: Astrometrics I
3) Items - Probes (Goes into more detail later in this tutorial)
Quest Probe - Astrometrics I
Persuit - Astrometrics II
Comb - Astrometrics III
Sift - Astrometrics IV
Here are the list of signals and the type of site to expect. Read this and understand it before choosing a signal to hone in on.
UNKNOWN: Combat sites. Can be found with ANY PROBE TYPE - Can also turn out to be any type of site.
GRAVIMETRIC: Hidden asteroid belts
MAGNETOMETRIC: Archaeology/Salvage profession sites
RADAR: Hacking profession sites
LADAR: Gas Cloud sites
COMBAT: These tend to involve lots of shooting. Currently there's very little reward in the initial sites you find, and the 0.0 ones in particular are REALLY hard. However, each combat site has a chance of escalating, which will give you a time-limited bookmark in your journal to the next site in the "escalation chain" - the journal entries are stored in the "Expeditions" tab. This site will in turn have another chance of escalating you to the next site, and so on. If you reach the "final" site in each chain, you may be rewarded with some faction loot. Also, a word of warning - leaving an expedition site before completing it may result in your expedition being terminated there and then.
UPDATE: These sites can now be found with internal sensors.
MINING: These generally have roids better than you'd expect in whatever security status (high, low, 0.0) you're in. Some sites are better than others. Often they'll be guarded by Rogue Drones or other pirates, and normal belt rats may spawn too. Asteroids in these sites do not respawn - once they're gone, they're gone
HACKING: These will have a bunch of Hacking structures in. Hacking targets look like cans in your overview, but have models that look like structures. If you try to open one, it will tell you you need proper tools. Target it and activate a Codebreaker module on it and your ship will try to hack it. If it succeeds, you can open the can and loot it. This is chance-based, so it may take several cycles to succeed. Hacking sites drop Datacores, Data Interface BPCs, Decryptors and other invention gubbins
ARCH/SAL: Short for "Archaeology/Salvage", these generally contain some Archaeology cans and some Salvage cans. Again, they look like cans on the overview but have other modules, and tell you you need tools to open them. Generally, anything that sounds like a broken ship (eg, Derelict) needs to be salvaged, while anything that sounds like wreckage (eg, Ruins) needs to be Analyzed (archaeology). Doing a "Show Info" on a can should tell you what tools you need to access it. These sites drop lots of rig parts, the occasional T2 rig BPC and Invention skillbooks
GAS CLOUDS: These are used for Booster-related stuff
Note: You will need to be able to atleast us a comb probe to find an exploration site. In short each probe has a lower scan radius but lower scan deviation. Also exploration sites seem to spawn within 1 and 4 AU of planets in system.