Today FamilySearch posted a database called New Jersey Probate Records 1678-1980.https://www.familysearch.org/search/collection/show#uri=http...
Despite the title, this appears to be county surrogate (probate) records from approximately 1800 (or the formation date of the county, if later) to approximately 1900 (in some cases later). A quick review of the records for several counties suggests that all the county probate records for the period I noted are posted. This includes, wills, inventories, letters of administration, petitions, guardianships, etc., etc., etc. All 21 counties are represented. These are the same records that you would find if you went to the county surrogate's office.
The trick here is to know how to find what you want. FamilySearch has no index for these records. I can't say that I am surprised; it would be a massive project.
However, the records for each county (at least as far as I have checked) do include an index.
Generally speaking, here is the process to find the person you want.
Click on browse the records, then click on the county you want. Under that county name you will find many files. Look for a group of files that include the word index. Some counties call them Surrogate's index, Docket index, Estate index, or whatever. There may be several books with that name. Look for a title that includes the first letter of the surname you want. Example for Union County: Surrogate's Docket index 1857-1949 H-R. I am looking for the name Meeker, naturally.
First, look at the first several pages of the book. There are usually additional instructions for finding the name you want. The plan varies from county to county.
The index file called H-R actually contains several books on the same film. The first section is H-K. The second one is L-M, etc. You will need to find the very first page for the group of surnames you need. That first page will have a key to finding the exact surname.
I found the page that I needed at image # 332. This page shows the scheme for indexing L & M names. Union County happened to use the Lusk system of indexing, which separates names according to the first 3 letters of the name.
The large M is the first letter. Drop down to EGH for the second letter. Then read across under E for the "page" number which is 1581.
From here on you have to guess how far along in the book you think # 1581 will be. You know the book is divided into 3 sections. There are 924 images. You are already at image #332, just starting the 2nd 3rd of the book, so I guessed at 550, which was too far, and backed up to image 536. Note the "page" number 1581 on the top right. (The first Meeker listed was in 1859 because Union County wasn't formed until 1857.)
There are 3 pages that include Meekers, with the last entry in 1948.
I am interested in Ephraim Meeker whose estate was probated in 1870. On the right side of the page note: Docket # 1374, page # 344, case #20.
I located the file for Surrogates Dockets 1857-1949, nos. 1-2000. This will contain Docket #1374 that I am looking for. It will be listed on page 344. Since there are two pages per image, I took a guess at image #175 and came pretty close. I found the record I needed on image 179.
The right side of the record for Ephraim Meeker shows all the books and pages where additional information will be found. The administration bond will be found in Adminstration and Guardian Bonds, Vol. B, page 276.
Additional loose papers will be found under the Estate number 1374 in the numbered Estate files. I have not yet located the books for inventories.
The process for locating records is similar for most larger counties: a two-index process. 1. Start with the name to get another index 2. showing specific files, books and pages for each type of record.
As I recall, some smaller counties have a one-step index. Find the person's name in a master index and all the index entries you need will in columns to the right of that name. The columns often cover two pages, so be sure to look on the next page also.
Since it is difficult to work through this process if you have never used it before, I suggest that new users concentrate on doing all the work they need in one county before moving on to the next one (which may well have a different system entirely).
There is lots of gold to be mined here, it's just a matter of finding it.
By the way, Ancestry posted the NJ Archives Calendar of Wills 1670-1817 in May, along with Will indexes up to 1900. For estates before about 1800, you may want to re-read the post here.http://boards.ancestry.com/localities.northam.usa.states.new...
Good luck with your searches!