I got 2 lists displaying invoice details, now my boss wants to read specific field from these two lists into a third list, any help will from anybody out there? I'm new to SharePoint.
You could make a console application to do the initial move, then add a WorkFlow on the two lists that make it so that if anything is added to one of them, it´ll copy the changes to the third list.
Are the two lists too big? if so you should take a look at the WSS upgrade API. It contains methods to do bulk copies; afterwards, the easiest way to transfer individual items is making an event receiver that listens to the itemAdded event.
You can check out Bamboo Solutions List Rollup (http://store.bamboosolutions.com/ps-32-5-list-rollup-web-part-release-34.aspx).
Why move the data into a third list? The reason I ask is that a view/report using a webpart such as the Bamboo web part mentioned could be a solution (there are others as well).
If you need to move the data, but only need to do it one time, then using something like Datasheet view to manually copy/paste can work pretty well. If the source lists are fairly large but not huge this can still work well but you only want to paste in batches (say 100 rows at a time). Datasheet view requires client integration which is typically turned on in most environments.
Outside of that, I suspect you'll need some custom script or code. Using PowerShell you can have a lot of power, or you can write a console app as recommended by another.
My thought goes to Sharepoint Lookup functionality, since your boss just want read specific field. The only problem is you need make sure lists located in the same site.
If you boss move data, Kirk is solution could help.
If you boss intend to make a data view which contains literally all the data from other lists then you do need some third party tools.Like SharePoit List Collection which can do more than that or Bamboo Solution mentioned above.