There are several different types of Jedi out there, but most fall into one of three categories: Lightsaber focus, Force power focus, or a mix of both.
A jedi build is almost always going to be a multiclass build. I have narrowed these classes down to four core classes based on the typical abilities of Jedi. These classes are:
Monk - Jedi are agile, strong-minded, use meditation to focus on the Force, and possess unmatched martial prowess.
Paladin - Dedication to the Light side of the Force aligns Jedi to Lawful Good, and their commitment to driving out the evil Sith puts them on a path similar to that of Paladins. Courage, Honor, Faith, Purity, and Strength - these are the values of Jedi and Paladins alike.
Cleric - While there is no religion tied to the Force, many Jedi still possess cleric-like abilities. They can use the Force to heal themselves and others, and there are many Force powers that work like cleric spells (blindness or blindness removal, True Seeing, Hold person)
Sorcerer - The majority of Force powers utilized by Jedi work like spells cast by Wizards and Sorcerers. I chose sorcerer over wizard because Jedi have strong personalities, and this plays more into Charisma-based skills than Intelligence.
So now we have our four main classes for building our Jedi - Monk, Paladin, Cleric, and Sorcerer. The first step is deciding what kind of Jedi you want to play, and this where you choose a type from one of the three categories.
Lightsaber focus: Your Jedi will focus mostly on Monk or Paladin classes. If you want more fighting abilities, you will put most of your levels in Monk. If you want more passive/support/buff abilities, you will be mostly Paladin. Cleric levels don't really have a purpose with these builds since you will only take 2 levels in it, at most. 6 levels of Paladin will be able to do what 2 levels of cleric can do. so either 12 Monk/6 pally or 12 pally/6 Monk and finish with 2 levels of Sorc for 3 strong buffing spells (Shield, Jump, Nightshield for example). Extend Spell would be good to get the most use out of your buff spells.
Force power focus: Your Jedi will focus mostly on Sorcerer or Cleric classes. A high Cha Cleric means great turning ability and lots of uses of Turn-related clickies. This makes for a great support-role Jedi. Sorcerer as your secondary class will give you some good buff spell choices. Finish with 2 Pally for the class's great abilities or 2 Monk for evasion. The other choice is obviously the offensive Force power role. This one would probably be best with 18 levels of Sorc and 2 of Pally or Monk. If you choose Monk and wish to use Longswords (lightsabers) be sure to take the feats Longsword Proficiency, Weapon Focus: Slashing, and Whirling Steel Strike so that you can use them as Ki weapons and remain centered.
Finally you have your mixed focus. This will combine your melee capabilities with both buffing and offensive force powers. Good choices for this type of build would be 12 Pally/6 Sorc/2 Monk, 12 Cleric/6Monk/2 Pal, 12 Sorc/6 Pal/2 Monk, etc. Figure out what spells and abilities you want and from there you can decide which classes to choose and how many levels of each you will need.