A fantastic collection of open-source plasmids and viral vectors. Addgene.org is also a great information resource for molecular cloning, genome editing, fluorescent proteins and much more. Their protocols and handbooks are excellent.
NEB is the Doble Lab's source for restriction and cloning enzymes and a wide variety of molecular biology kits. This site is also a great resource for numerous protocols and troubleshooting advice.
Benchling is a great resource for generating plasmids in silico. It is free for Academic use and has become a vital tool in the Doble Lab. Check it out!
If you want to know more about your gene of interest, this is one of the places to check out. Here you can find out where your gene is located within a particular genome, your gene's structure, splice variants, alternative start sites, etc. It is a fantastic resource that the Doble lab uses alot!
Integrated DNA Technologies (IDT) is not only a great source for synthetic oligonucleotides and DNA segments, their website has numerous useful online tools.
Another great site that can be used to find out more about your gene of interest. Tools include the excellent genome browser, BLAT, In-Silico PCR, and numerous tools that allow you to delve deeply into the genome by viewing a wide variety of tracks that indicate the locations of epigenetic marks on histones, transcription factor binding sites, etc. This is another tool that is used frequently by the Doble lab.