I could not find this information anywhere on the site and have had to rely on trial and error plus tips from Alliance members, so I thought I 'd share what I learned.
This post is NOT about where to get medals. It is the actual step by step process of attacking.
First of all, I should clarify the terms being thrown around. It took me a bit to figure out what was what.
There are 3 types of attacks:
1. Attack Valley - "Valleys" it seems, are any piece of land that does not look like a village or castle. They can be Flatlands, Grassy, Hills, Swamp, Lake. If you click on one, it will be in one of 3 states: 1. Owned by a non alliance player (attackable) or 2. Owned by an alliance player (reinforceable), 3. Owned by noone (attackble). The latter is the ideal one to attack.
2. Attack NPC - These are cities owned by barbarians and much harder to attack. There are posts on how to attack these.
3. Attack Player - This is the juice of the game and you'll get to these much later.
This guide focuses on attacking valleys. Why attack valleys? There are 2 good reasons to attack valleys
1. Gain medals - In order to gain prestige, complete quests, get promotions, build more cities, you must acquire a set number of certain medals. Refer to your quest screen under promotions.
2. Gain experience for your heroes - A victory against a valley grants experience to your heroes. Enough experience allows you to upgrade your heroes. From what I gathered, which hero to select for attacking for Valleys all depends on which one you want to level up. Just be careful to send a little more troops if your hero has below 60 atk power. When upgrading heroes, only upgrade their highest attribute and leave the rest low.
Before you start your FIRST attack make sure you have at least 1000 warriors, just to be safe. Recruit a hero with at least 60 of your chose attribute. Make sure you have at least 2 heroes because one of them will be your mayor and he/she can't leave town.
OK, Here's the actual guide
1. Scout a low level valley as close to your city as possible. For your sake, try a level 1. This should take less than a minute. Edit: You should not need a hero for scouting on level 1's.
2. You'll get a scouting report that will tell you how many soldiers there are in that valley.
3. Now Attack that valley with 10x the soldiers and your chosen hero. i.e. If it has 150 mix match soldiers, send 1500 warriors. Edit: You can throw in some archers, how much? Youll have to use the Exercise screen in the Rally Point screen. I've been told that a 10:1 ratio increases the probability. This will take 10-60 minutes depending on how far you are from your valley.
4. Once the valley is defeated, you'll get an Attack Report. Read the report, scroll down. That will tell you if you got a medal (or not), how much experience your hero got and a few others.
5. Recall your soldiers. Returning to your city will take the same time as attacking.
These next 2 steps are speculation. From what I've read recently, it may be better to leave that valley alone for an hour (from your last attack)
6. When they arrive back at your town, click on the valley you attacked earlier and abandon it and immediately...
7. ... Repeat Steps 3 to 6 over and over again until you get the medals you want. Don't get disheartened if you don't acquire any medals after 10-15 attacks, It's happened to me before.
Once you get more confident, make more soldiers and do 2-5 attacks on other valleys. Of course, you'll have to build more warriors.
My goal was to get just enough medals so that I could get my promotions on rank and titles so that I could build more cities.
Start attacking higher level cities as your need for medals start to require higher level valleys.
1. Rather than abandoning a valley as mentioned in Step 6 above, go attack another one. Having a Flag on a valley increases your resource production based on what's shown for the tooltip. So just recall your soldiers and don't abandon. However, you can only put up as many flags as your Town Hall Level. ie, if your Town Hall is level 4, you can take advantage of 4 production bonuses.
I hope this was helpful. If anyone needs to correct anything, please post here and I'll do my best to update this, if I have the rights.