Online Game - Aside from choosing talents, one of the most difficult things to figure out while leveling is which glyphs you should choose. Obviously, different glyphs are geared towards different playstyles and situations, and as such, it can be way too complicated for someone new to the class to figure out what works where. Thankfully for you, I've put together this handy primer that takes the guesswork out of it and saves you from wasting gold on trying out different glyphs.
1. First Major Glyph (Level 15) - Glyph of Judgment. Your Judgments deal 10% more damage. Pretty self-explanatory. Paladins are not exactly DPS gods at lower levels, so this is definitely a good boost in the right direction, and since you'll be using a Judgment spell every time it's off cool down, there's no rocket science involved here.
2. First Minor Glyph (Level 15) - Glyph of Blessing of Might. Increases the duration of your Blessing of Might spell by 20 min when cast on yourself. Another simple choice. Retribution means smashing, and smashing means Blessing of Might. Less self-buffing means more mana for smashing. It's an easy choice.
3. Second Major Glyph (Level 30) - Glyph of Seal of Command. Increases the chance of dealing Seal of Command damage by 20%. By the time you can get this, Seal of Command should be your primary damage Seal, so increasing your chance for it to activate by 20% is a pretty sweet deal. You will notice a serious DPS upgrade with this glyph, much more so than with any other of your choices at this level.
4. Second Minor Glyph (Level 50) - Glyph of the Wise. Reduces the mana cost of your Seal of Wisdom spell by 50%. When you need to mana up, the less you have to invest to get yourself refilled, the better. Since you'll probably still be using Blessing of Might most of the time at this level, it's not worth grabbing any of the other minor glyphs yet.
5. Third Minor Glyph (Level 70) - Glyph of Lay on Hands. Reduces the cooldown of your Lay on Hands spell by 5 min. At this point it's less a question of "What's most useful?" than it is "What's less useless?". This glyph is mildly useful if you find yourself in bad spots more often than you should, but in general it's just filler. If you find yourself using other Blessings frequently, or you plan on grinding a lot of Undead, you may find one of the other minor glyphs more useful.
6. Third Major Glyph (Level 80) - Glyph of Crusader Strike. Reduces the mana cost of your Crusader Strike ability by 20%. It's nice to go longer without drinking. Since you'll be using Crusader Strike every time its up, this works out to a good bit of mana saved in the long run. If you find yourself in more AoE-friendly situations, you may want to get Glyph of Divine Storm instead.
Remember that what works for me may not necessarily work for you. If you find that one of the glyphs isn't working for your playstyle, swap it out for another that augments a spell you use more. All in all, I feel that the set of glyphs I detailed are the best selections for their level, and are the ones best suited to the standard tasks associated with leveling. Happy hunting!