The Wikipedia explanation is pretty good, but doesn't really cover your question:

Steps to Christ is an evangelistic book written by Ellen G. White, co-founder and prophetess of the Seventh-day Adventist Church. It was first published in 1892 by Fleming H. Revell Company. The copyright was purchased by Seventh-day Adventist publisher Review and Herald Publishing Association in 1892, and was first printed there in 1896. A new first chapter, "God's Love for Man" was added per request of the Seventh-day Adventist publishing house in the United Kingdom (Stanborough Press) in 1893 in order to secure a copyright. This is perhaps the most popular and widely read book by the author, printed in more than 150 languages worldwide.^[1]

Steps to Christ discusses how to come to know Jesus Christ at a personal level. It covers the topics of repentance, confession, faith, acceptance, growing into Christ, and prayer.

This information did not used to be readily available, so I did not know about it for around 20 years, until the 2010 GC Session in Atlanta where a EGW Estate person told me that.  He also said something about that first chapter being compiled, but I'm not sure if he told me the source, or if I forgot.

I do know that something is very fishy about that book.

First, it wasn't even printed at the publishing house that Ellen White worked tirelessly to create and support.  The R&H saw it selling well at Fleming H. Revell, and decided to buy the copyright to it in 1892, something they could have had for free!

Second, Uriah Smith, the chief editor, was outed by Ellen White in 1892 (year when 1st published), as being the man who had caused her work more harm than any other during the previous two years.

Third, some of the wording in the first chapter sounds suspiciously close to what Kellogg was teaching - pantheism

Fourth, it is clearly admitted that she did not write this to be the first chapter of the book, so even if it is from her, it is possible that it gives a different impression by being placed here than the author intended.

-------------------------

It appears that at least some of the exact wording might have been in Patriarchs and Prophets, as it first came out in 1890.  However, I have no original copy of that book, so do not know for sure.  Similar wording is also in the 1894 "Christian Education" book.

Personally, I believe the book makes much more sense, and flows in a logical progression without this new first chapter "God is Love".