For my part, I would like to offer an excerpt from Williston Walker’s John Calvin: The Organizer of Reformed Protestantism (also available from the current publisher). Walker’s biography of Calvin was the most thorough and most acclaimed in the first half of the twentieth century, among English-language biographies of Calvin. Walker, who was an esteemed professor of church history at Yale, benefited from the massive resurgence of Calvin scholarship in the late 19th / early 20th century, paralleled by a resurgence of studies on Luther. Since then, we have benefited from the more recent biographies from T. H. L. Parker (1975), Bernard Cottret (1995), and Bruce Gordon (2009), among others. They each have their invaluable contributions toward understanding Calvin’s life, but I have especially enjoyed Walker’s biography.
Walker is not afraid to offer analysis and conjecture, with appropriate evidence of course. Calvin’s life is notoriously obscured by the minimal amount of self-reflection on Calvin’s part and even a minimal amount of contemporaneous reflections from friends. But here is a nice example of where Walker ventures to exhibit Calvin’s “winsome” character as a student in Paris:
Besides the more intimate friends already mentioned, it is probable that Calvin’s membership in that portion of the student body known as the “nation” of Picardy would bring him into close touch with all students or instructors of prominence who regarded his native region as their home. But, as these relations are inferential rather than a matter of proof, it is easy to insist upon them too much. It is evident, however, from such friendships as have been described, most, if not all, of which were now formed, that the young student at Paris must have been of more than ordinary attractiveness and charm. To win the regard of such a man as Cordier, to hold the affections of young noblemen like those of the house of Montmor-Hangest, who assuredly were under no obligation to continue a friendship had it proved irksome, above all to gain the goodwill of a family of distinguished station and scholarly eminence like that of Cop, bespeak unusual winsomeness in a student of relatively humble birth, with little save himself to offer. Nor is the quality of his friendships less illuminative as to his personal character. To attract a Cordier or the household of a Cop certainly indicates a nature attuned to the better and finer side of life. No student of low impulses, or unrefined tastes, or of a misanthropic, uncompanionable disposition, could have won the permanent regard or made the lasting impression that Calvin did upon those whose friendship it was an honour to possess.
Yet legend, reflecting it may be the severer traits of his later life, has ascribed to the student Calvin a censoriousness of judgment in his relations to his companions, and an unsociability of temper, that, if true, would paint for us a very different portrait of the young scholar whose experiences at the University of Paris have just been reviewed. A story, credited by Le Vasseur to Calvin’s brilliant renegade one-time friend and disciple, but afterward enemy and calumnist, Francois Baudoin (1520-1573), relates that his fellow students called him “the accusative case,” because of his denunciatory spirit. It is unnecessary, however, to weigh the question of Baudoin’s degree of truthfulness, as the statement is not to be found in his own published controversy with Calvin, and has no real foundation. A degree of plausibility is given to it, it is true, by Beza’s declaration regarding the friend whose biography he was writing that, as a student at Paris, Calvin was not merely very religious, but a strict censor of all vices among his associates (severus omnium in suis sodalibus vitiorum censor). Student life, as is abundantly witnessed not merely by the satires of Rabelais, but by the sober letters of Erasmus and of many less distinguished scholars, was apt in that day to be lawless and vicious enough; and an earnest, religious, and scholarly youth, of refined tastes, such as Calvin was, could have had little sympathy with its cruder excesses. But that he was misanthropic, of unfriendly spirit, or was regarded by his associates with aversion, there is no adequate evidence. The facts point to an opposite conclusion; and he appears at the completion of his course under the Faculty of Arts, in his nineteenth year, a student of high personal character, great linguistic and dialectic promise, able to make and keep friends whose interest in him must have been primarily due to the attractive qualities of head and heart which he revealed to them. The report of his successes at the University must have pleased his old patrons, the canons of the cathedral at Noyon, for in September, 1527, they added to his ecclesiastical holding the curacy of Saint-Martin de Martheville. The increase in his income was considerable, and the purpose which impelled the gift can have been naught else than a desire to aid a brilliant young fellow-townsman in his studies, for the relations of Gerard Cauvin to the chapter were already such that the benefice cannot have been given for the father’s sake. Certainly the young student from Noyon was well treated by the friends who had known him in his boyhood town and, in turn, must have possessed qualities which commanded their regard.
[John Calvin: The Organizer of Reformed Protestantism, pp. 41-43]
Once again, I highly recommend Walker’s biography, alongside the others mentioned above. I would start with Walker.