EVE General Discussion

The problem is too many people do the exploration, especially in high-sec. So it requires time and patience to find something.
To scan every signature until it is clear that this signature is not what you are looking for is a waste of time.
http://swiftandbitter.com/eve/dsp/
Pay attention to this site. With this you can just scan the entire system with an only probe expanded to its maximum scan range (deep space one is desirable, but a simple Core Scanner Probe is fine too). Click the appropriate link (high-sec in your case), type the Probe Sensor Strength and voila! You can tell what exactly is in your system, and even which signature exactly to scan. And if there is nothing of interest - warp to another system.
Right-click your scanning ship with the Core Scanner Probe charged and choose Show Info item. Switch to the Modules panel, find your probe charges there and check its info. Doing this way you can see the probe sensor strength taking into account all bonuses from your current skills, ship and probe launcher.
Good luck.

OP, sounds like you need to fix your filters. CCP in their infinite wisdom have the cosmic signature types all set off by default. Basically, once you get more than a certain percentage signal strength, they will get filtered out. Go into your scanner filter and check Radar, Magnetometric, Ladar, and Gravimetric tick-boxes.

Also, for exploration use Sisters Core scanner probes and a sisters launcher. Get into a Covert Frigate and rig it with Small Gravity Capacitor rigs. Until then, use the bonused Tech 1 frigate of your choice. I like the Imicus for it's 15m3 drone bay and 15Mb drone bandwidth. Orbit at range and let your drones kill the enemy. Fit a MWD and your analyzer/codebreaker in mids, salvager and probe launcher in highs, and whatever you need in your lows. You should be able to handle any hacking or salvage/archaeology sites you come across ni hisec. DED combat plexes are a bit tougher. You'll likely need a more combat oriented ship for those.