Hi Russell. I have a little experience because three sets of 3x great-grandparents are from communes (towns) that are now part of Bas-Rhin, but I am not an expert by any means. What I did at first was to open a page in my browser, then copy the URL into another browser tab to have Google translate the page into English for me.
The website is Archives Départementales du Bas-Rhin
Near the top of that page is a tab that says Rechercher (Research). The webpage that follows has three columns near the bottom. The first is old documents that I have never explored so not sure what all is there. The second column will take you to parish and civil registers and the third column takes you to census records for 1819, every five-year-censuses from 1836-1866, 1881 and 1885. Click on Consulter (Consult) to get to the records.
You need to know the name of the town to go further. (Type Cleebourg into the white box where it says Votre commune and click Rechercher if you just want to have a look.) The next webpage looks like a long bookshelf with books and years written underneath. Shown first are the Catholic and then the Protestant church registers. If there was a local synagogue, there might also be records for it. Church registers usually end about 1792–sometimes earlier. Next are 10-year indexes starting in 1793 (hopefully!) and ending in 1942. Finally are the Birth (N), Marriage (M) , Death (D) and sometimes Marriage Proclamation (PM) registers. Beginning in 1811, the registers are preprinted forms making them easier to translate with Google. I think birth and marriage records online end in 1912 and death records in 1922.
Double clicking on a book will open it. To get back to the bookshelf, click on Retour Adeloch, not your browser’s back button.
Hope that helps!