Start with Lord Foul's Bane. It is book one of ten and there is no alternative route — the series is one continuous story and the later books assume the earlier ones in detail.
Read the first hundred pages before committing to anything else, and read them knowing what is in them. About a hundred pages in, Covenant rapes Lena, a sixteen-year-old girl who has just helped him. It is written on the page, it is not ambiguous, and it is not incidental: the rest of the ten books are built out of it, its consequences drive the plot of the second and third volumes, and the series never stops returning to it.
If that is a hard no for you, stopping at page one hundred is a completely legitimate choice, and you are not missing a later scene that redeems it. The series does not offer one. Making that decision at the start rather than three books in is the single most useful thing an order guide can do here.
The First Chronicles
Lord Foul's Bane, The Illearth war, The Power That Preserves.
Covenant is a leper, and leprosy here is a discipline as much as a disease — the daily inspection, the refusal of hope, all of it brought into the Land as a survival protocol. The Land itself is a place of health so intense that a leper's nerves come back, which is exactly why he cannot afford to believe in it. His refusal to accept that it is real, because accepting it would kill him at home, is what makes him both useless and dangerous.
Donaldson is writing directly against the Tolkien template: a chosen one who declines the role, and a fantasy world whose beauty is presented as a trap. Lord Foul's Bane is also the roughest going stylistically and takes three or four weeks at 25 pages a day; the two that follow read considerably more smoothly.
This trilogy is a complete story, and many readers stop after The Power That Preserves with no sense of loss.
The Second Chronicles
The Wounded Land, The One Tree, White Gold Wielder.
The Land's natural law has been replaced by the Sunbane, a rotating cycle of sun-phases forcing growth, rain, pestilence and drought — corruption expressed as ecology. It only registers as horror if the healthy Land is fresh in your memory, so do not leave more than a few weeks after the first trilogy.
Linden Avery arrives as co-protagonist and is the reason many readers prefer these three: a doctor whose percipience makes her feel other people's illness, so she cannot look away from anything. Her own history of complicity is deliberately built to rhyme with Covenant's without excusing his. The Wounded Land is bleak and slow to start; The One Tree is the most conventionally enjoyable stretch in all ten books; White Gold Wielder is short and heavy.
Donaldson wrote White Gold Wielder believing he was finished, and it reads that way. It is a genuine ending.
The Last Chronicles
The runes of the earth, Fatal Revenant, Against All Things Ending, The Last Dark.
Be realistic about these. They are the longest, densest and hardest of the ten, and the most commonly abandoned. Written nearly two decades after White Gold Wielder, they assume near-total recall of the first six — read them soon after, or reread a synopsis first, because the time travel through the Land's own history in Fatal Revenant punishes hazy memory brutally.
Against All Things Ending is the slowest volume in the series and the one most readers stall in. Knowing that in advance is the difference between pushing through and concluding the series has failed.
Linden is the lead now, and Covenant's absence is structural rather than incidental. Thousands of years have passed in the Land, so almost every institution you know has changed or gone. The reward is that The Last Dark actually closes arcs opened in Lord Foul's Bane forty years of publication earlier. There is no eleventh book.
Where to stop
Three defensible answers. After The Power That Preserves you have a complete trilogy. After White Gold Wielder you have the work as its author once thought it finished, and this is the recommendation for most readers. After The Last Dark you have everything, and you will have earned it. For other long sequences with the stopping points marked, see the rest of the site.
Follow the full ordered path here: The Chronicles of Thomas Covenant Reading Order: Where to Start.