Need help harvesting pleaseFollow

I've only harvested a few times, I usually mine, but I'll try and help you out as best I can.

First off is equipment. Make sure you have a Field Tunica, Field Boots and Field Hose. These items all have Improve Harvesting, which basically reduces Sickle breaks and harvesting failures. I personally don't think they increase the "good" items, but others feel they do. Either way, reduced breaks and failures will greatly improve your success with mining, and the items will pay for themselves very quickly.
Another "item" you need is increased Gobbie Bags, you'll fill up very quickly. Gobbie Bag 3 or 4 probably would be a great start, but the bigger the better. Also make sure your inventory is as empty as possible. Also make sure you bring several stacks of Sickles, I'd recommend 3 or 4. NPC vendors sell cheaper than AH, and if you're harvesting you'd probably be in Windurst. In Windurst Waters at the Ensasa's Catalyst shop in the north map the taru npc sells Sickles.

Create a Sickle macro, so you just can run up to a point and slice away.
/item "Sickle" <t>

Another very important tip is have rudimentary skill in Clothcrafting. Not sure exactly the skill levels you'd need, I personally only have 4, just enough to turn Moko Grass into Grass thread, then Grass thread into cloth, since you'll be harvesting alot of that. Also bring a few stacks of Lightning and Earth crystals of course.

Having the maps of the areas you'll harvest at is just common sense. Also print out maps with the harvesting points already on them, and as you get to that point in the game, create a Marker there. After a while you'll get to know the exact <pos> by heart, but starting out it's very valuable.

I think you can only Harvest in West Sarabu-whatever, and Giddeus. The Giddeus points are located through out the area, but the West Saru-place are on the ledges near the Giddeus zone. It's hard to describe exactly.

If you need more help you can search around other FFXI sites and look for H.E.L.M. (Harvesting, Excavation, Logging and Mining) guides.