First, download the source books we are using. I have listed the source books I am allowing in the other topic, and you can find the character generator there as well.
Read through the Player's Handbook to learn how to play. After this, read through the races and classes outlined in the different sourcebooks. Make sure the race you are looking at is playable. It will have an "as player characters" section if it is not in the playable race section of the sourcebook. Figure out which race and class you want to play, and proceed to the character generator. You may not apply any templates to your character (werewolf, half-dragon, ghost and the like), and you may not select any race with more than a +1 level adjustment. Select the "Standard" option when rolling for stats. Assign your stats based on the class you want to play. Check the box for the race you wanted to play, and the box for the class you wanted to play. Fill in any relevant information to your class, and assign your skill points. Read through the "Feats" sections of certain sourcebooks and check the boxes for the feats you want to take. Do not select any feats that are not from the sourcebooks allowed. Pick the weapons you want to use and any other gear you want your character to have (don't forget waterskins and rations, even though I probably won't pay much attention to those). If your character has skill points in Speak Language or knows other languages due to their race, check the boxes for the languages your character knows. Select an animal companion if you have one, AND DO NOT SELECT ANY TRAITS. Select a height and weight, choose their hair/eye color and other appearance options, name your character, give it a title if you'd like, make sure you give your character a decent backstory, and click "Generate Character." Post your character sheet in the other topic or in it's own topic in my board, and wait for approval.
When rolling for attacks, you roll to hit and then roll for damage. The roll to hit is 1d20+any modifiers you may have that increase or decrease it. The roll for damage depends on the weapon you are using, and whether or not you scored a critical hit